Diesel engine swap

[hatzie]

Originally Posted by SKR

That's because LSs are a cult. I asked a shop well known for big power LS builds if it would be cheaper building a big block or an LS. The only condition I had was 500lb-ft at 2500rpm. He told me there was no possible way to get a big block to do that without going to all expensive forged parts, and that an LS was the only way to go. He then showed me a build they did recently that almost made that torque, for $17,000. Meanwhile I can buy a 502 from GM for $8500. Only a cult member would come up with something crazy like that. I don't care how good the mileage is, $8500 buys a lot of gas and the 502 will do it on 87.

LSs have their place, but low end torque isn't it.

The cult of the Big Block exists as well.

There's also the cult of the diesel and more specifically the cult of Cummins.

11mpg is more than a little optimistic on the 454 and fairly pessimistic on the 6.0L. My average on the 6.0L is 12.5mpg over the last 2 years.
The 6.0L LQ4 swap on my brothers' truck cost right around $600 for the plugs & wires, motor mounts, water pump, oil pump & pickup, fluids, and recently the $259 GMPP LQ9 cam. The engine and transmission was essentially free before the repair parts, camshaft, and motor mounts. It's a non AC truck so the AC compressor went away... if you want AC it'll cost ya.
It was a lot of work to re-purpose the GMT800 harness & PCM as a stand alone setup and the motor mounts were not drop-in parts either. I did have a complete running rust bucket as a donor if you're buying from a salvage yard you're going to get raped with no lube.

You have to weigh a bunch of factors. Location enters into the equation as well.

Want's...
-If you're towing all the time you're better off to get a diesel. The maintenance cost is higher than gasoline and the cost of a donor engine or truck is plenty high as well.
-The 454 or 8.1L Vortec are a second best for full time towing but the fuel mileage is pretty scary. The 8.1L is pretty pricey and the 454 is old enough now that you will be unlikely to find a reasonably priced un-molested core to rebuild. Rebuild parts that aren't from China will cost you as well... despite what the cult of the big block tells you.
-My 6.0L is much more to my liking than the big blocks and diesels I've owned for the occasional towing I do. Maintenance is fairly low and it gets decent fuel mileage. Mileage is not as good as a diesel and not as bad as a big block. It's roughly on par with my 305 & 350 smallblocks over the years. You'll pay a fairly healthy price for any LS truck in the salt free desert states, non-coastal South, and Pacific Northwest. You're competing with salvage yards and flippers for wrecks in the salt free states. You can find rust bucket donors fairly cheap in the salt states.

None of the three are remotely affordable if you're stuck with crate engines or bending over and grabbing your ankles for the junkyard goons.

Modifying engines for performance costs you reliability and lifespan. That's the way it is. Some mild mods are less detrimental but they do cost you on lifespan.

I have an 86 K20 to work with right now. 350-SM465-NP208-10bolt front-9.5" 14bolt rear. It needs a new engine. I'll rebuild the original 350 smallblock and run it with a rebuilt Rochester Quadrajet, cast iron intake, mechanical fuel pump, cast iron manifolds, and stock HEI. I am replacing the beat up 10 bolt with a rebuilt Dana44 and the burnt up 9.5" 14bolt with an already rebuilt 10.5" 14bolt. Probably pretty boring for you guys but it'll still be running well 150,000 miles after I'm done with the re-build.