All too common LS swap vs unique old school small block

Agree on torque. The BBC will obviously have better torque. For a big, heavy truck or doing heavy towing, the old saying about displacement holds true for NA. For a lightweight RCSB, even a STOCK LS 4.8 with right gearing would be an upgrade over OP's worn out 4.3. I'm really liking the LS coil-on-plug ignition system and the injector system over the SBC in my case. No more distributers to wear out and goofy spider injectors to deal with; those 2 alone are worth upgrading to if OP wants reliability in my opinion. Diagnosing an engine with that is much more easier than the other older system.

I bought an 8.1 engine/Allison combo pretty cheap from a guy that does square body/GMT400 swaps. Guy had a shop and we talked a bit. It was all LS in the engine bays of the 3 trucks he was working on at the time, all 1500s of course. I just saw a YT video on a guy that tears down blown engines and he stated the 454 Vortec he he was tearing apart was 650 lbs with accessories. My plan was to swap into my K3500 because I never really found any 454 Vortecs in about 4-6 months looking...I mean they've only been discontinued 22 years, LOL. It's probably because they made less BBC than SBC, but they seem to be almost extinct around here. Even SBCs are getting rare, along with GMT400s in general.


I just realized OP never mentioned BUDGET... That's the first thing we should of asked! LOL. Some guys here have spent $500 on engine swaps. Others more like $5,000+ on built engines. Budget matters. Then there's the NV3500, which I don' think it will be happy with V8; certainly not with a souped up V8 or BBC, so add a grand (or two?) for that upgrade.

They did sell NV3500's behind 4.8s. I think they're all basically the same too.

I'm going to run mine until it blows up and then I'll get something stronger. A lot of how long it lasts is how you drive it.

NV4500?

stutaeng said:

NV4500?

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I'm thinking TKX.

Cool. What about the ZF6? They are kinda rare though. They came in a few 8.1 & 6.6 TD GMT800s. And a lot of Super Duty Fords had them for much longer than the GMs.

Seems like the TKX is more suited for a fast truck? Sorry, I don't know anything about manual transmissions.

stutaeng said:

Cool. What about the ZF6? They are kinda rare though. They came in a few 8.1 & 6.6 TD GMT800s. And a lot of Super Duty Fords had them for much longer than the GMs.

Seems like the TKX is more suited for a fast truck? Sorry, I don't know anything about manual transmissions.

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I think those came on the C4 Corvette too.

Yeah, I want a more race suited transmission but with an overdrive. I'd really love one of those fancy sequential manuals, but I just can't justify spending $XX,*** on a transmission.

I think you should ask yourself what do you want to get from this? Are you doing this for more power? Is this something you are doing for fun? Swapping a SBC or a BBC would be easier and quicker an LS swap might be more interesting to do. With the SBC and BBC aftermarket upgrades are getting harder to find and are usually expensive. With the LS there's all sorts of things you can do to get some more horses. I swapped my 5.7 for a 383 . I'm happy with it. Lots of torque but after it was done for a couple months I wanted to do more to it (for fun not because I was dissatisfied) and there's not a lot of options without doing an egr delete and I have to go through emissions. It's a daily driver so I don't want a huge lopey cam in it. I agree with DerekTheGreat when he said to ignore what other people are doing. Do what interests you and gives the most enjoyment. You want to do something unique, make it a mid-engine and mount the engine behind the cab. That way you'd have a huge trunk up front People would really freak out when you started loading your groceries into the front of your truck.

0xDEADBEEF said:

But we're talking about the present. There's just way more LS truck motors at the junkyard, and the aftermarket support is better. I watched a Richard Holdener video last night where he dyno'd 20 different LS intake manifolds. 20! Maybe there are 20 different Mk 6 BBC intakes out there, I don't know, but I doubt it and they aren't as easy to get.

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But the Gen6 454 was in everything, vans, uhaul trucks and county trucks it is cheap because everyone wants an LS or LT, just about everything I own is a Big Block my 78 crew cab with a Mark IV, my 95 K3500 with a Gen5 and I’m building a Gen6 with EFI from a boat because the intake has long runners for toque production for the 78. Everything about the Gen6 I’m working on has me looking for another one for my 79 GMC Jimmy, The Gen6 basically are the LS electrically with a 28 tooth reluctor on the crank coil near plug and direct port injection. If you throw a standard distributor and a carburetor it’s four wires to get it running, it’s the simplest drop in swap.

PedroC said:

But the Gen6 454 was in everything, vans, uhaul trucks and county trucks it is cheap because everyone wants an LS or LT, just about everything I own is a Big Block my 78 crew cab with a Mark IV, my 95 K3500 with a Gen5 and I’m building a Gen6 with EFI from a boat because the intake has long runners for toque production for the 78. Everything about the Gen6 I’m working on has me looking for another one for my 79 GMC Jimmy, The Gen6 basically are the LS electrically with a 28 tooth reluctor on the crank coil near plug and direct port injection. If you throw a standard distributor and a carburetor it’s four wires to get it running, it’s the simplest drop in swap.

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I couldn't do that in my state with our truck. Have to keep the computer if we want to drive it on the road.

0xDEADBEEF said:

But we're talking about the present. There's just way more LS truck motors at the junkyard, and the aftermarket support is better. I watched a Richard Holdener video last night where he dyno'd 20 different LS intake manifolds. 20! Maybe there are 20 different Mk 6 BBC intakes out there, I don't know, but I doubt it and they aren't as easy to get.

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You are dead wrong on aftermsrket big block support. Just look at Summit.