Why waste time with swapping in a measly 396 or 427? If you're going to go big block, this one doesn't weigh any more (ok, maybe that tranny does) and it doesn't take up any more room under the hood. I see they are rated at 440 +/- ft-lbs from basically off-idle to about 4200 where peak power is listed as only 330 to 340. Given what they do with an LS3, I can guess what a little tweaking might do here. I mean, 496 CID at 9.1 compression? 500 HP should be an absolute no-brainer. Buying the whole truck would probably be cheaper than trying to source all the electronic piece meal.
I would not want to buy the gas, but hey, it runs on regular.
Wouldn't it be fun though. You might want to buy stock in Goodyear.
If this one doesn't make you stop and daydream for at least a few seconds, you probably have the wrong hobby...
You would also need to disable the torque management in the ECM. A friend had a dually with an 8.1 and it was a slug when empty. Hook on an equipment float and it would fry the tires!
Paul
As far as I know the bell housing bolt pattern is the same. The Vortec 8.1 is an animal all to itself. I dont think that any older big block parts will fit.
Paul
We have this in our 2007 gmc 4wd firetruck, it doesnt care if its loaded or empty, cruise at 120 without any annoying automatic shifts.
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63 Parisienne sport coupe (The Big GTO), black, maroon interior, 409 4 speed; former owner of a 59 El Camino, 63 Corvette SWC, 62 Chev Bel Air SC. 1963- Pontiac top selling car in Canada
Mahone Bay, NS Still not old enough to need an automatic