I have seen a few things in searching for an answer here and there, that does prove that people have put the GM 383 motors into bigger trucks. Most the info I read says the HT383E motor is a direct swap for a 350, but mostly says in 1/2 ton trucks. I am looking for an answer and/or opinion about putting this motor in my truck, and if it’s possible, maybe a good parts list as well. My truck is a ‘99, CCLB K3500. It is absolutely all stock, with a NV4500 5 speed and 350 motor, with 345,000 miles on it. The truck is still running pretty good, but is starting to get a little tired, so I’m working on getting my list together and mentally prepared to take the plunge, and really hope to add more power over the 5.7, using the 383 if truly it is a candidate for my truck.
Thanks
As you can see from my signature, I have done this swap in a 3/4 ton truck. From my own research prior to this swap and from the people I've talked to, my best guess is simply that GM didn't bother to re-certify the emissions for this swap on anything but a 1/2 ton vehicle. I can confirm that it works great and there are no issues with the factory PCM or aftermarket tuners. In fact I'm fairly certain that there's no difference in the factory software between a 1500 and a 2500. I'm guessing the 3500 also.
I also looked at the 454, but that's not a direct drop in swap plus I was concerned about future inspections or emissions issues which the HT383E has no issue with.
Because of it's slightly hotter cam and roller lifters, the HT383E puts out power numbers similar to the factory 454 anyway. With minimal work, you can well exceed the stock 454's numbers fairly easily.
Stock 454: 290 HP @4000, 410 lb-ft @3200
Stock HT383E: 323 HP @3200, 444 lb-ft @3000
This is without other upgrades. Using G-Meter type tests mine is closer to 400HP/500lb-ft by adding good airflow from intake to exhaust, including headers, and a performance tune. Plus I'm still "legal". At this point I don't regret going with the HT383E over a stock 454 at all. Plus the HT383E has heavier duty components like forged crank, roller rockers, etc. which was my main reason for going with this swap, gaining a tough, reliable engine that would last a long time and tow like a son of a gun. All mission accomplished.
The only thing you'll want to watch is your RPM. With a stick it's easier to blip up past redline and I wouldn't want to do this to a stroker like the HT383E regularly. No biggie, just a thought.