Lt1 with a th400
 

Got a 66 catalina, and a 96 LT1. Considering carburating it and bolting it up to the original 400 trans. Anyone done a swap like this? Obviously money is the issue, plus I already have the LT1 sitting around. Looking for some different perspectives. aaahhhhhhhh!!!!!!!!!!! :poke: :poke: please help

I've bolted them to t-350's is your t-400 a BOP unit? If so you will need an adapter.

trans
 

it would be a BOP trans. heres another issue, which Torque converter to use? aftermarket ones for 400's or the switch-pitch ( i think thats what it's called) that comes with it originally?:drum:

I would keep the efi to try and run a newer motor, with carb it would be like a reg 350 sbc with decent heads and a h/r cam. I own a 94 Z28 w/LT1 (as well as 68 and 70 GTOs)and is definitely a better runner than some of my buddys "old school" 350s/327 etc. But...in a heavy car (factory installed impala ss, caprice cop car) it's not quite the same. I would imagine a 66 fullsize is a bit more weight than that of the newer full size gms. Factory is about 240hp+/- at rear wheels.The stock 389 was lower, but probably more torque. It would be ok to install with carb/th400 if all you want to do is have something that runs I guess. I would use an o/d trans as well also.I would build a 383 stroker mild cam combo w/efi and od trans if you wanted a little more power and be somewhat efficient. But then again a nice stroker 400(455) would probably be a better tugboat motor as it would have alot more low end. An Lt1 would need headwork and cam to get good torque but would be at a higher rpm. Also a sbc/Lt1 in a fullsize pontiac would need a custom mount arrangement as they don't have the same frame as the chevy cousins. good luck