I have a 2001 gmc reg. Cab with stock 4.8 found an 8.1 how hard
will it be to swap it out will the stock trans. Hold up
thanks for any help

 

I suggest using the search feature for a few days for this one

Buuuuut- you'd be better off $$ wise sticking to the small block LS family, and your stock trans (assuming it's a 60E) would be a good breakfast for that 8.1

 

It's very true... The biggest motor the 60E is mated to is the 5.3L for a reason, it's not built to take much more than the 5.3 can dish out. Putting an 8.1 in front of a stock 60E would turn your transmission into just a spray of transmission fluid and loose chunks of metal. If you're going to do an engine swap, it should probably go hand in hand with a tranmission upgrade as well.

 

Yessiree, if you could get an 8.1 to bolt to a 60E, I doubt that the 60E would make it out of the driveway lol. But just to clarify, the 65E, which is basically a 60E with 5 pinion planetaries, came joined to the LQ9 6.0 in the SilvySS, VortecMax, etc.

If you want to swap big cubes into a GMT800 truck, look into a 6.0, or a stroker such as a 408, 418, etc, and if you go much more than a NA 6.0, plan on swapping in an 80E or once again you will have a trail of 60E behind you