Building a SBC...

[kfgk14]

So, I wasn't really sure where to post this, but I have a series of dilemmas...
I'm a highschool student, with a low budget from my parents and hopefully a job this summer to supplement that budget...
I have this dream in my head of a Chevy square body, single cab truck...1-ton running gear, small block engine, NV4500 transmission and an NP205 behind it, just a simple truck, minimal electronics, preferably carbureted for the sake of not screwing with wiring and the associated costs/time drain...
I'm willing to do any and all work I have the tools to do myself, but my parents really aren't the mechanic types so I have very limited tools. I can borrow a lot of other tools I'll need through the automotive tech program at school and other contacts I have, and I will buy what I have to when I can afford it (can actually write some amount of the expenses off as an educational expense on my folk's taxes and they'll pay for it in that case, don't ask...convoluted story with my school administration, short version I'm making this a project at school).
Let me give you, briefly, the objective of the build, and a rationale as to the above choices in terms of drivetrain:
The truck needs to be a utilitarian 4x4 I can take a long way from home, drive hard off-road in harsh environments, fix with hand tools in the middle of nowhere (though I'd prefer none of that-hence the 1-ton running gear) and also do tasks like tow a trailer, haul various and sundry heavy things my dad loves to drag home in borrowed trucks now, and look studly as **** for prom next spring (getting the ladies is, of course, key )
I wanna go square body as opposed to OBS Ford or Dodge because they're relatively plentiful around my area (Dodges are unobtanium here, Fords...I don't know, I'm just weird about Ford, not that I don't like them but...I don't know, I'm just not building a Ford, there are more Bowties here anyway) and I have a burning desire to build a SBC. Why SBC and not a diesel? I want to build a SBC (one of those things I've wanted to do since I started to study automotive things), they're ubiquitous and relatively straightforward, and I definitely want to be cool-guy with a V8 (again, the ladies...:coffeedrink. Note: I don't need gut-wrenching torque and horsepower, but I want the truck to be able to hold top gear well on the highway, take decent grades easily, and make good low-end torque so it can deal with Hummer take-off 37's I intend to put on when I can afford it
I have this idea of a 383 stroker in my head...I've heard things, good things, that they don't chug quite like a 454+ but they have far more torque and horsepower than a standard 350 and the blocks are tougher than 400's...So I'm sort of hoping you guys can give me some advice:
Can I build a 383 that will net good horsepower gains and torque gains over the 350, and not put fuel away like beer at Oktoberfest? Can I do it for under, say, $1500 if I shop carefully (fully built, carburetor to oilpan)? Would I save a lot of money (like, locker money) if I just did a mild 350 build and accepted less horsepower? Would the fuel economy of the two engines be radically different?
Is it cheaper to just accept the pooh mileage of a 454, build a 454 very mildly, and drop that in, put the savings in gas? Can I find a 454 or similar that doesn't need a build, just tuning, and can go in and put out good torque and fun horsepower, or is that a pretty rare score?
On transmissions... (enjoying this text wall yet?)
I love me a manual. I'm still occasionally stalling out during my lessons with my friend across town, but I'm loving every clutch-dumping moment :coffeedrink:
His truck has the NV4500, and I like it. Are the chevy NV4500's gonna be $$$, or can I get one for pretty cheap (junkyard/pulled, not rebuilt obviously) and drop it in? Do they need special adaptation for the old SBC blocks, or will it bolt right up with a stock bellhousing? Could I get away with an NV3500, depending on the engine?
Now...one other question...(I know, shut up kid, seriously this lil brat goes on forever huh? )
Does it make sense to buy a CUCV M1008 and pull the 6.2D/TH350/NP208 combo and sell the drivetrain to keep the body/frame/axles? Or should I buy a truck already set up with a clutch assembly and hopefully a 350 block/NP205 inside? I can get an NP205 pretty cheap around here, but is it worth the hunt? There are always CUCV's and such around, and I like the gearing/axles under the CUCV as they're bomb-proof with lots of aftermarket. Is that something I need to address case-by-case?
I'm sure some of this is subjective/case-by-case stuff. Sorry I'm really dropping a broad spectrum of stuff on ya'll.
Also, if there's a better place to take my engine questions, I'd be happy to take them there instead of drowning you guys.

 

[Rot Box]

I can understand wanting the simplicity of a carb however if you are considering any technical/hard off-roading I would highly recommend a V8 with the TBI injection found on the 87-95 GM's. Its debatably just as simple as the emissions cluttered Quadra-Jet, its cheap, easy to troubleshoot and they work very well off road. If you could track down the elusive 87 you'd gain the TBI and square body style. Just a thought...

As always I recommend building off your needs and not wants. Find a cleanest square body GM you can then hit the trail. You'll quickly see what works for you and what doesn't. I'd shoot for a 3/4-1ton for increased drivetrain strength. Pass on the 454--If you were planning to haul a 5th wheel it would be another story but for what you have in mind I think you'd hate the fuel mileage imo.

Anyway there's my opinion and keep us posted :bike_rider:

 

[bfdiesel]

First not sure about your rebuild price been along time since I helped build a 383 it was alot of work not bad just more than just rebuilding. More research to make sure you get it right more custom work to clearance the block.
For hardcore offroading a carb is going to leave you lacking, but for milder stuff it will be fine.
I would vote with rotbox, find a square body you want, run it and see what works for you. Then build from there. If you are wanting H1 wheels and tires looking for a dually ( not a cab and chassis ) out of the gate would be a good idea. 14 bolt hubs on a Dana 70 dually will make it the same width as the front dually axle. NV4500 are pricey and didn't get into gmc's till 92, you will likely not find one already in what you want. You will need a 32 spline input np205 for a nv4500 they mostly came behind TH400's
Chevy's are like lego's almost all the pieces will interchange there are some little things that need to be paid attention to, but for the most part just bolt it together.
Until you know more of what you have to start with, it is hard to give you advice.

 

[kfgk14]

First not sure about your rebuild price been along time since I helped build a 383 it was alot of work not bad just more than just rebuilding. More research to make sure you get it right more custom work to clearance the block.
For hardcore offroading a carb is going to leave you lacking, but for milder stuff it will be fine.
I would vote with rotbox, find a square body you want, run it and see what works for you. Then build from there. If you are wanting H1 wheels and tires looking for a dually ( not a cab and chassis ) out of the gate would be a good idea. 14 bolt hubs on a Dana 70 dually will make it the same width as the front dually axle. NV4500 are pricey and didn't get into gmc's till 92, you will likely not find one already in what you want. You will need a 32 spline input np205 for a nv4500 they mostly came behind TH400's
Chevy's are like lego's almost all the pieces will interchange there are some little things that need to be paid attention to, but for the most part just bolt it together.
Until you know more of what you have to start with, it is hard to give you advice.

Thanks for the guidance, same to you rot box
On using dually axles, is there machine work involved in putting 14BFF hubs on a D70 dually axle, or do they basically just bolt up? Also, can high/crossover steering be installed on a DRW D60? If keeping the high-offset H1 rims isn't practical (would sorta like them for the beadlock, this truck will come out west with me for college and get wheeled hard there as well as back east) I can just get some cheap 16.5" steel wheels with a more manageable backspacing, and eventually add an internal air beadlock system when funds allow. I don't anticipate needing the beadlock until at least college when I'll have access to Moab and such.

Is there any carb system (the modern "truck carbs" I see advertised in the Edelbrock and Holley catalogues, maybe?) that can keep up off-road, or are they just destined to fail in off-camber situations? If FI is the only way that's fine with me, I'm just somewhat partial to the "ideal" of a carbureted engine, guess that's the old-fashioned upbringing shining through.

 

[Metcalf]

Big project for sure.

I like old trucks, but they are just that, old trucks. Be prepared to rebuild just about everything if you want a reliable truck. The good news is that with most of the older 1970s stuff that everything IS rebuildable or serviceable.

I imagine your going to have to fight a decent amount of rust issues out east on a truck that old?

Unless your set on a shortbox truck I would just get a 3/4 ton version and have half the one ton axle swap already done. You can use a dually front axle with the H1 wheels easy enough but it still ends up a bit wide overall in my opinion.

If you want to run a 37" tire I would be prepared to do some trimming, sectioning, and moving the axles around a little on the truck instead of just lifting it.

The stock push/pull steering system stuck on dodge and chevy trucks. I would plan on converting it to a crossover style system if at all possible, especially if the axles get pushed around a little or it is lifted a little.

On the engine. A properly tuned carb can work just fine off road. The key is knowing how to build and tune it. Personally I think the autolite/motorcraft 2100/2150 2bbl carbs are the best you can get off road. With a little work they will run at angles that you won't want to drive on. If your dead set on building an engine I would just do something mild like a normal old 350. More cubes can be fun but without airflow to support them you can only go so far. Pushing 37s around at highway speeds your probably going to get 10-15mpg for the most part.

Honestly, if I was going to rebuild an old truck like that I would look at finding a low mile newer 5.3 engine and swap that in. They make 300hp stock, fuel injected, and will run for 150-200K with very little if any work. You can get a complete pullout for what a decent SBC engine rebuild would cost. You can sell your original engine to make some of the money back after the swap too. Engine technology has come a LONG way in the last 30+ years.

Good luck on your project!

 

[Mobryan]

Thanks for the guidance, same to you rot box
On using dually axles, is there machine work involved in putting 14BFF hubs on a D70 dually axle, or do they basically just bolt up? Also, can high/crossover steering be installed on a DRW D60? If keeping the high-offset H1 rims isn't practical (would sorta like them for the beadlock, this truck will come out west with me for college and get wheeled hard there as well as back east) I can just get some cheap 16.5" steel wheels with a more manageable backspacing, and eventually add an internal air beadlock system when funds allow. I don't anticipate needing the beadlock until at least college when I'll have access to Moab and such.

Is there any carb system (the modern "truck carbs" I see advertised in the Edelbrock and Holley catalogues, maybe?) that can keep up off-road, or are they just destined to fail in off-camber situations? If FI is the only way that's fine with me, I'm just somewhat partial to the "ideal" of a carbureted engine, guess that's the old-fashioned upbringing shining through.

Not sure about this hybrid 14b/D70 thingy, but if you need more width than the stock 14b dually rear, SRW 14b hubs bolt on, use the same axles shafts. SRW hubs add 4" to the width (2" per side). I'm not sure if there is a combination of stock brake parts that would work w/o moving the backing plate, but I'd probably go to rear disk anyhow. RuffStuff fab has disk brake brackets for any combination you can imagine. Off Road Design has kits for anything you want to do with a Chevy.

Good Luck!

 

[kfgk14]

Big project for sure.

I like old trucks, but they are just that, old trucks. Be prepared to rebuild just about everything if you want a reliable truck. The good news is that with most of the older 1970s stuff that everything IS rebuildable or serviceable.

That's the fun, isn't it?

I imagine your going to have to fight a decent amount of rust issues out east on a truck that old?

yeah...most likely...

Unless your set on a shortbox truck I would just get a 3/4 ton version and have half the one ton axle swap already done. You can use a dually front axle with the H1 wheels easy enough but it still ends up a bit wide overall in my opinion.

Definitely going with a long bed, plan on a sleeping platform and camper shell once the mechanical side of things is better sorted. I think I may just buy steel wheels and pull the 37's off the old H1 rims for the sake of simplicity.

If you want to run a 37" tire I would be prepared to do some trimming, sectioning, and moving the axles around a little on the truck instead of just lifting it.

Definitely. I'm inspired by your work on the Doitall, big rubber down low looks mean that's my game plan. Save money I would have to blow on springs and put it toward...

The stock push/pull steering system stuck on dodge and chevy trucks. I would plan on converting it to a crossover style system if at all possible, especially if the axles get pushed around a little or it is lifted a little.

...Steering! My research over on Pirate4x4 as well as your project put this high on my list. Once I sort the drivetrain situation, steering is next.

On the engine. A properly tuned carb can work just fine off road. The key is knowing how to build and tune it. Personally I think the autolite/motorcraft 2100/2150 2bbl carbs are the best you can get off road. With a little work they will run at angles that you won't want to drive on. If your dead set on building an engine I would just do something mild like a normal old 350. More cubes can be fun but without airflow to support them you can only go so far. Pushing 37s around at highway speeds your probably going to get 10-15mpg for the most part.

Glad to hear my carburetor dreams are realizable.

Honestly, if I was going to rebuild an old truck like that I would look at finding a low mile newer 5.3 engine and swap that in. They make 300hp stock, fuel injected, and will run for 150-200K with very little if any work. You can get a complete pullout for what a decent SBC engine rebuild would cost. You can sell your original engine to make some of the money back after the swap too. Engine technology has come a LONG way in the last 30+ years.

I guess I didn't spell out well enough, that a big part of this is the experience of the build, not just the end product. I'm actually on track to major in automotive technology at Weber State University in Ogden, Utah. This is sorta gonna be my crash-course in fixing mechanical things, as a prep for going to school. If I was just building it to drive and own, I wouldn't be considering a build. But rebuilding an engine is something both my parents are pushing me to do and get experience with...Their money so I'm not complaining

Good luck on your project!

Thanks for all the insight, PS I dig your work and can't wait for your "chasing unicorns" build to get rolling!

 

[Metcalf]

Thanks. The Long Jeep is going to be a LONG project. It is the next thing on my list for sure but I need to get a lot of ducks in a row. Getting the tub seems to be a bigger hurdle than I thought....

If you want to build an engine by all means do. A 383 small block would be fun. You can get the rotating assemblies pretty affordable now. If you buy a running truck I would just plan on finding another engine block to use as a donor for the engine build so you can keep the truck mostly intact and driveable during the engine build. I ran one of the larger Motorcraft 2100 carbs on my old FE block 390 in my truck back in high school. The larger version of the 2bbl is rated for about 400cfm. A lot of people love to think about 4bbl's up to the point they have to pay for fuel every day. I was way more happy with the 2bbl on my 390 than the 4bbl. Its not like you need to drive around at 5000rpm all the time anyways.

Number one thing if you end up with a carb. Spend the $170 on a wideband 02 gauge! Best money I ever spent on my little Willys. It has taken my carb tuning to a whole new level.

Are you thinking manual or automatic?

16.5 wheels suck unless they are beadlocks. I wouldn't waste the money. For the price of a set of sucky 16.5s you could recenter the H1 wheels. Personally I would try and upgrade to 17s and find some used tires to get you buy. The hummer tires are not THAT great in my opinion.

Don't forget your going to need to do something for gearing in the axles with the 37s. Finding a truck with factory 4.10s would get you pretty close if your not running an overdrive.

Chop, cut, section, trim, roll, push, bulge, weld, move axles, build steering, and whatever else you want. It's just metal. Your at a really good age to learn. One of the best things about using a GM product is that you can pretty much build a new truck with an LMC catalog these days. You can get just about any sheetmetal part. I think you could even build a new body if you wanted I hope this project happens for you...

 

[bfdiesel]

14 bolt hubs go right on a 70. Disc brakes will also be the best way to go.

 

[kfgk14]

14 bolt hubs go right on a 70. Disc brakes will also be the best way to go.

Really? Hmm...new options opening up...

Are the hubs available aftermarket/rebuilt/remanufactured somewhere?

 

[Mobryan]

any junkyard will have the hubs, and all you need to put new bearings in is a basic array of hand tools. The only remotely specialized tool would be a 6 prong (2 7/16"??) socket to remove the bearing retaining (spindle) nuts. With the 14B hubs, the outer bearing does NOT come out the front of the hub like a Dana axle. All bearings come out the backside of the hub, there is a large snap ring that retains the outer bearing /race. Pry the snapring out, then drive the bearing and race out the back of the hub.


Matt