My current truck is a gasser, and has dual batteries. because it's EFI, it has a fuel supply and return already as well. I will need to change the sending unit in the tank for a diesel sender, or use the TBI pump as a lift pump. of the things you list, the only one that I don't feel like messing with is hydroboost, mainly because I just redid the brakes. all that being said, I am keeping my eyes out for a replacement for this truck, the body is pretty rough from getting sideswiped by a drunk a few weeks ago. I do plan to stick with a Suburban, either a 1987-91, or a 1967-1972 GMC Suburban
Diesel engines
- Thread starter ejs262
- Start date
My current truck is a gasser, and has dual batteries. because it's EFI, it has a fuel supply and return already as well. I will need to change the sending unit in the tank for a diesel sender, or use the TBI pump as a lift pump. of the things you list, the only one that I don't feel like messing with is hydroboost, mainly because I just redid the brakes. all that being said, I am keeping my eyes out for a replacement for this truck, the body is pretty rough from getting sideswiped by a drunk a few weeks ago. I do plan to stick with a Suburban, either a 1987-91, or a 1967-1972 GMC Suburban
D
Deleted member 9101
Guest
I'd probably go with a mildly built 6.0 gasser and call it a day.
Honestly, if I go the 6.0 route, it will stay stock, or as stock as possible to swap it into the truck. I need reliability, and range. my 2006 2500HD had enough power for my cross country trip last year, towing my car on a trailer. the flipside, is that it gets 11 MPG dry, and only has 33's. I don't drive like a 16 yo either...
usanumber1
Member
I currently have a 6.5TD in my suburban, but go Cummins and don't look back. Especially as your truck is a squarebody, you'll have plenty of room, and there are many mfgs making conversion parts to ease the job. I have a 12 valve in my shop almost completely prepped and ready to drop in my 1999, I can not wait to get it in there. My generation 6.5 doesn't cool as well as other engines, has problems with no-starts (all related to electronic control of IP). The Duramax is cool, but it's also A LOT of work because there are so many electronics involved. The mechanical Cummins wires are as follows: oil pressure, water temp, throttle position (for trans controller), boost, EGT, alternator, air conditioner, water in fuel. It should be noted that none of them are required to run the engine. If you went really slim on the wiring, you could get that down to 3 wires.
jonathon
Active member
MPG isn’t everything and a diesel swap something you do because you want to not to save money.
The nice thing about an SBC or to a slightly lesser extent the LSx is you can walk into any auto parts store and get what you need. My TBI v2500 with a 4” lift, 35’s, and 4.88 gears managed 13 mpg highway. I had a 4L80E, which was nice. Didn’t need seem to matter how much stuff I put in it either. What’s funny is my K1500 with a 700r4, 3.73 gears, and 31’s only gets 13.5, but still has the old catalytic convertor on it where the ‘burb just had a muffler.
Is your stock engine in good shape? Your L05 block is likely set up for a hydraulic roller cam. Mild cam, Vortec heads, and either a tune or an aftermarket EFI setup and you may be surprised. After taking a peak inside my engine this is the route I’m likely taking.
The nice thing about an SBC or to a slightly lesser extent the LSx is you can walk into any auto parts store and get what you need. My TBI v2500 with a 4” lift, 35’s, and 4.88 gears managed 13 mpg highway. I had a 4L80E, which was nice. Didn’t need seem to matter how much stuff I put in it either. What’s funny is my K1500 with a 700r4, 3.73 gears, and 31’s only gets 13.5, but still has the old catalytic convertor on it where the ‘burb just had a muffler.
Is your stock engine in good shape? Your L05 block is likely set up for a hydraulic roller cam. Mild cam, Vortec heads, and either a tune or an aftermarket EFI setup and you may be surprised. After taking a peak inside my engine this is the route I’m likely taking.
1stDeuce
Explorer
I vote 6.5L TD if you can find a decent one... I had a '96 that was a great truck. The duramax is expensive, the Cummins will likely require 4-6" of lift if you don't already have it, and it's heavy, even compared to the 6.5L.
I believe the 6.5L crank issues were most common on manual trans trucks that had been turned up. (Like mine, which broke the crank at about 300k miles, or about 10k after I sold it...) The automatics go far longer before there's any danger, and if you get a gently driven manual, I'd bet it'll see 400k before any concern. The later water pump and dual thermostat along with an early Duramax fan took care of all my cooling problems. I pulled the engine cover off the top, and never had an issue with the PMD, though I did carry a spare just in case...
Downside to the 6.5 is that that truck version has a side mounted turbo that will require you to cut up the heater box some on your square body. The van/HMMWV version has a top mounted turbo that might be a better swap...
The high compression is actually one of the things that makes the 6.5L great in my opinion. It has EXCELLENT engine braking, and mine always started in the cold, even with 4 burnt out glow plugs. The lower boost level also means no need for an intercooler, which is necessary on the higher boost options.
I've actually considered that if the 6.0L in my 2002 GMC ever dies, a 6.5L would make a great replacement engine. (It's my snow plow truck, dump truck, and around town beater...) I have a duramax, but sometimes, I do miss my old 6.5L.
I believe the 6.5L crank issues were most common on manual trans trucks that had been turned up. (Like mine, which broke the crank at about 300k miles, or about 10k after I sold it...) The automatics go far longer before there's any danger, and if you get a gently driven manual, I'd bet it'll see 400k before any concern. The later water pump and dual thermostat along with an early Duramax fan took care of all my cooling problems. I pulled the engine cover off the top, and never had an issue with the PMD, though I did carry a spare just in case...
Downside to the 6.5 is that that truck version has a side mounted turbo that will require you to cut up the heater box some on your square body. The van/HMMWV version has a top mounted turbo that might be a better swap...
The high compression is actually one of the things that makes the 6.5L great in my opinion. It has EXCELLENT engine braking, and mine always started in the cold, even with 4 burnt out glow plugs. The lower boost level also means no need for an intercooler, which is necessary on the higher boost options.
I've actually considered that if the 6.0L in my 2002 GMC ever dies, a 6.5L would make a great replacement engine. (It's my snow plow truck, dump truck, and around town beater...) I have a duramax, but sometimes, I do miss my old 6.5L.
usanumber1
Member
This is not the case. No lift is required, but a 1-2" body lift makes it easier.
My L05 is a flat tappet engine, no provision for roller cam, I had the engine out to replace the rear main about 6 months ago, and ended up having to put a crank kit into it.it runs ok, doesn't make much power, I'd hate to pull a trailer with it in the mountains. if it stays a gas burner, it'll be an LSx, they're inexpensive, and make way more power and torque compared to a traditional smallblock, and maintain some economy. I think mine gets about 10-12 MPG hwy, 350/700r4/np208 3/4 ton axles with 4.10's Mine is also on 4" of lift, but with 33" BFG KM3's.
Funny you mention HMMWV engines, I've started looking into them. I'm bummed, because one went at an auction for $25! unknown condition, but, for $25 it would give me something to use for mock ups and things like that. I also like the V mounted turbo because of how tight it it in the engine compartment. if I do a 6.5, I will intercool it, the other thing I would like to do, is lower the compression ratio. which is another reason way missing a $25 engine is a bummer... I'm beginning to like the 6.5 more and more, I really like keeping engines and transmission all from the same manufacturers, it simplifies interface to the vehicle quite a bit.
chet6.7
Explorer
FWIW,
www.4btswaps.com
Cummins 4BT & Diesel Conversions Forums
A forum community dedicated to Cummins 4BT Diesel owners and enthusiasts. Come join the discussion about performance, modifications, troubleshooting, engine swaps, transfer cases, and more!
www.4btswaps.com
nickw
Adventurer
Stick with a gasser, that's my vote. That's what it was designed for, will be the easiest to do and likely the most reliable since nothing needs to be highly customized. The simplest, and most reliable, thing to do is just have your stock engine built up a bit. Those Cummins are going to add a hundreds of pounds to the front of that rig and are loud.
No reason you can't get 10-15 mpg in a well tuned V8....
How about a Ramjet 350? Super simple, very reliable and good power #'s. Although I like what somebody else posted, get the 502!
No reason you can't get 10-15 mpg in a well tuned V8....
How about a Ramjet 350? Super simple, very reliable and good power #'s. Although I like what somebody else posted, get the 502!
Buliwyf
Viking with a Hammer
Split the difference with a 383:
www.summitracing.com
I don't think Al heads are worth the extra $1000 for a burb, but they sell those as well.
BluePrint Engines BP3830CTC1S BluePrint Engines GM 383 C.I.D. 405 HP Vortec Stroker Dressed Long Block Crate Engines | Summit Racing
Free Shipping - BluePrint Engines GM 383 C.I.D. 405 HP Vortec Stroker Dressed Long Block Crate Engines with qualifying orders of $109. Shop Crate Engines at Summit Racing.
I don't think Al heads are worth the extra $1000 for a burb, but they sell those as well.
tgdoumit
Adventurer
I swapped a 12 valve Cummins into my 88 burb. I really like it very much.
Yeah, there was some serious shoe horn action going into the build but the end result is fantastic in my book.
I like the simplicity of the motor but in stock form it’s only 220 hp / 440 flbs torque. But it’s totally upgradable.
It requires very little wiring.
I put a standard transmission in mine, Dodge NV 4500. It was behind the motor in my donor. I like it but I think an auto like what I had in my 24 valve CTD would have been nice.
Mine has been on the road for about 6k miles now and it just works wonderfully.
Driving an old square burb 60 miles every day is pretty great.
Whatever you do will be fun in the end.
I get better than 20 mpg and I haven’t added anything to the motor yet. I plan on more horsepower but nothing more than 300ish total.
Sent from my iPhone using Tapatalk
Yeah, there was some serious shoe horn action going into the build but the end result is fantastic in my book.
I like the simplicity of the motor but in stock form it’s only 220 hp / 440 flbs torque. But it’s totally upgradable.
It requires very little wiring.
I put a standard transmission in mine, Dodge NV 4500. It was behind the motor in my donor. I like it but I think an auto like what I had in my 24 valve CTD would have been nice.
Mine has been on the road for about 6k miles now and it just works wonderfully.
Driving an old square burb 60 miles every day is pretty great.
Whatever you do will be fun in the end.
I get better than 20 mpg and I haven’t added anything to the motor yet. I plan on more horsepower but nothing more than 300ish total.
Sent from my iPhone using Tapatalk
vargsmetal
Active member
I helped a friend do a duramax/allison conversion on a C30. They fit really well, almost like it was made for it. Being the 2wd cab he did a 2in body lift to fit the trans without having to cut out the transmission tunnel. With the 4wd burb you should be good. Harness is easy to rework yourself, don't spend a lot of money on a reworked harness. I did his harness for him in an afternoon using a Bussman RTMR waterproof fuse box just like my 5.3L harness.
6BT is a great option, but more expensive to me by the time you get adapter plates and a computer to run a 4L80e or other GM trans. If you run the dodge trans it's not so bad, but it's not as good as a duramax/allison.
I read somewhere the stock 6.5 manifolds don't fit the narrower frame of the squarebody, but I could be wrong.
Another random option is the 7.3, but again with the transmission adapter or having to run a ford transmission.
I really like the 5.3L/4L80e that I replaced my 350TBI/700R4 with. It's a great combo and gets the same 18mpg the TBI did in my K1500. Plenty of get up and go, and I wouldn't hesitate to tow with it. Can't beat the cost/performance.
Given infinite budget my choices would be duramax/allison for diesel, or the L96 6.0L/6L90e for gas. There is no reason to go with an old sbc/bbc crate engine, huge waste of money for something more antiquated than what you already have.
Sent from my SM-G965U using Tapatalk
6BT is a great option, but more expensive to me by the time you get adapter plates and a computer to run a 4L80e or other GM trans. If you run the dodge trans it's not so bad, but it's not as good as a duramax/allison.
I read somewhere the stock 6.5 manifolds don't fit the narrower frame of the squarebody, but I could be wrong.
Another random option is the 7.3, but again with the transmission adapter or having to run a ford transmission.
I really like the 5.3L/4L80e that I replaced my 350TBI/700R4 with. It's a great combo and gets the same 18mpg the TBI did in my K1500. Plenty of get up and go, and I wouldn't hesitate to tow with it. Can't beat the cost/performance.
Given infinite budget my choices would be duramax/allison for diesel, or the L96 6.0L/6L90e for gas. There is no reason to go with an old sbc/bbc crate engine, huge waste of money for something more antiquated than what you already have.
Sent from my SM-G965U using Tapatalk