Thoughts on PowerPlant for possible Project

[dorton]

I have a 70' Chevy Blazer that has been sitting in my garage for the last 10 years or so. It is a very nice old rig, and just within the last couple weeks I've gotten the itch to start messing with it again. It has been probably 6 or 7 years since it was fired up. I changed all the fluids, sprayed some penetrating lube in the cylinders, pulled the coil wire and turned it over to prime the system. Plugged it back up, it fired up and purred like a kitten. Other than fuel leaking out of all the seals on the carb (was a brand new holley last time I parked it), I think it's going to be pretty good to go.

I have been contemplating purchasing a new rig, for camping exploring, and wheeling. Then it dawned on me, why not modernize my old rig?

Here are my thoughts. Replace driveline with more modern power. The 307 that currently resides in it is as weak as puppy pee, and get horrible mileage when combined with the 3 speed non o/d auto tranny. It also has 4 wheel drum brakes that need to be gone yesterday.

What's the community's thoughts on this as a project? I'll be doing some searching to see if there are any similar rigs.

thanks,
Dorton

 

[Buliwyf]

-Buy a 2008+ Chevy Express van with 200,000 miles or less as a donor vehicle. They're worth about 2-3 dollars. When my company trades thier fleet in, the dealer or someone, parts them out to sell as reman'd parts and scraps the body.

-Divorce mount a decent transfer case, maybe even your transfer case.
-Mount up the Chevy Vans stout 6.0L and transmission
-Perform Voodoo ritual to get vans ECM to work again and run the engine and transmission minus the van.
- Tow the truck to your local 4x4 shop for custom driveshafts.
-??????????
-Profit!

 

[1leglance]

Well as the owner of a 70 suburban I am right in your shoes.
In my case with a bigger rig I am going with a 6.2L diesel conversion...I bought a 87 burb and striped it clean of what I needed. Lucky for me no computer in that rig.

Disc conversion is easy.
Updating it all is easy.
And you are worth more later vs a new rig that is worth less each day.

If you haven't found it yet then 67-72chevytrucks.com is THE forum for us.
You don't mention your location but I am sure there is someone near you on this forum or that one.

Oh and please post up some pics...I love the full removable hardtop blazers!

 

[98dango]

I would be on a efi 5.7 or even a 5.3 or 6.0 full wiering 4l80e and run some newer disks

 

[pulltilbroke]

No suprise here but my choice of power in a rig like that would be a 4BT Cummins.

 

[Larry]

Welcome to the forum Dorton!

I agree with 1leglance, 67-72chevytrucks.com is the forum for anything GM truck related. Lots of nice folks that have swapped every imaginable engine into old GM trucks. It seems 6.0L/4L80E is the most popular swap into trucks these days. For an old K5, my preference would be a 6.0L/NV4500 5 speed manual backed by a NP241 transfercase. The engines are not horribly expensive used (or buy a complete donor vehicle as Buliwyf stated), brand new plug and play harnesses are reasonable and ECM’s are dime a dozen as well as ECM tuners that can calibrate the ECM to your vehicle needs. With the proper ECM tuning you will be surprised how much power, durability and economy you can squeeze out of today’s small block gas engines. Diesels are nice but get just as pricy if not more pricy than doing a late model GM Vortec swap and when a diesel breaks….pony up more big boy dollars. I like diesels too, I just haven’t found a diesel engine that I love enough to spend the time and energy swapping in to anything of my own.

Pre-1996 TBI 5.7L engines are even cheaper to come by and very easy to swap in. Here is a TBI 5.7L I swapped in to an old beater 1972 C20 a few years ago. TBI engines are not fast but they are extremely reliable and deliver decent fuel economy. This would be a very noticable economy and power gain over a toilet Holley carbureted 307!

Or of you want to get real crazy, find a 2001-2010 8.1L. High torque (600 lb ft), high HP (425) with TBI 5.7L type fuel economy.

 

[Rot Box]

Those Blazers (Jimmy's) are so cool :drool: we'd love to see some pics.

One thing is for sure the sky is the limit when it comes drivetrain possibilities lol. If I were to build one it would end up getting a 6.2 /6.5 diesel and an SM456 4 speed manual. Not the most exotic or powerful drivetrain out there, but it is one of the simplest and cheapest options while providing good fuel milage, strength and reliability.

 

[dorton]

No suprise here but my choice of power in a rig like that would be a 4BT Cummins.

that would be a very cool setup, but I know very little about diag/repairing diesels. I'd hate to be broken down looking for a part a few hundred miles from home.

For an old K5, my preference would be a 6.0L/NV4500 5 speed manual backed by a NP241 transfercase.

That sounds like a fun combo.

I'm going have to start spending a little less time on gun forums, and do some searching and investigating on this old rig. I spent just a little time over at 67-72chevytrucks.com last night.

I used to have a 95 2wd w/TBI, that wasn't exactly a power house, and as far as fuel mileage was, I could have cared less, at that time fuel was $1.65/gal.:smiley_drive: For this one, I'd like to build something that I can drive to CO,or WY without having to take out a 2nd mortgage. on the 5.3s or the 6.0 could mid teens mpg be a reasonable target?

 

[Rot Box]

that would be a very cool setup, but I know very little about diag/repairing diesels. I'd hate to be broken down looking for a part a few hundred miles from home.

Hmm. If a 4BT breaks down on the side of the road it can be one of two things. A. you've either ran it out of fuel or B. Forgot to add oil when you changed it last :bike_rider:

 

[MicroBird]

No suprise here but my choice of power in a rig like that would be a 4BT Cummins.

+1

 

[pulltilbroke]

A 4BT would be about 100 times simpler to diagnose on the side of the road or in the middle of BFE just because of the simplicity, just keep a few spare parts with you and go. You don't have any ECM/PCM or any wire controlling the motor unless you run a fuel shutoff solenoid instead of a pull cable kill. Also after you do the swap and fiddle with the pump to get a little more performance out of it you should know enough about the VE pump to get you by.

The only reason you would have an IP failure is if you run totaly crap fuel and don't have proper filtration or you run with a dead lift pump for an extended period of time. And if you did lose a pump "out there" its about 1 1/2 -3 hour job if your slow.

The 4BT would also get mid 20s-mid 30s for economy.

The pump on my 90 has 423,000 miles on it, has never been off the truck and has been turned up a lot for the last 180,000 miles with no signs of any issues. I would hop in that thing and take it anywhere at a moments notice.


Parts can be had at any parts store or Cummins dealer or big truck shop in the rare occasion that you might actually need somthing.

 

[Rot Box]

Those VE rotary pump and even the P pumps show signs of wear long before they die completely. The only Cummins pump I know that will leave you dead in the water without warning is a VP and they didn't come on the 4BT's that I know of.

As for trouble shooting they are probably one of the simplest engines I've ever turned a wrench on... Lawnmower and tote-gote engines included :bike_rider:

 

[dorton]

That sounds simple enough. My experiences with diesels is with ford in the late 90s through the end of 2004. During that time ford went away from the 7.3, and then released the 6.0. If you had a good one, they were great, if you had a bad one, we were going to be seeing each other a lot more than I was comfortable with.

I'm not going to rule that option out. I'm going to do some research on them. They sound pretty intriguing.

 

[1leglance]

I will agree that the 4BT is a dead simple engine..
However I still say the 6.2 GM diesel or the 6.5 (and a turbo on either) is a better swap.
They are bolt in configurations that are very close to the small & big block motors that came in these rigs.
You are also dealing with NO computer and a pretty basic injection pump.
Parts are maybe a bit harder to find than the 4BT but then again you can get alot of the 6.2/6.5 stuff at NAPA and such which isn't always the case with the 4BT.
Gas mileage will be pretty close between the two.
Honestly I guess for me it is the fact that I want a GM motor in my GM vehicle

But then again I haven't finished my diesel swap yet so check back with me later

 

[chilliwak]

Welcome to the site Dorton. Larry is by far the most experienced guy here for the newer Chevy motor swap. He knows his stuff!:Wow1: You could replace the motor with a diesel, but my question is why? A K5 Blazer is a light truck. A V8 will give you plenty of power....