Howdy. New member here. Been a member at LS1tech for a while, but figured I'd get better info here on what I need.

Have been building a '90 GMC 1500 over last few years. 4/6 Drop, Custom interior, cowl hood, custom paint, 18" wheels, BFG DRs, etc, etc.

Just got done with a 383 stroker build. Very potent. 4.11 gears. Now...the problem. Still running the old manual 5-speed which is a huge lunky piece of junk. I have no idea what the motor is putting out yet and don't plan to find out until I change the trans. The motor is a brand new block...got rid of the old Vortec.

I did a search on T56 in here, but doesn't look like it is suggested. If slight fabbing is needed that's OK, but looking more of a bolt and go deal.

Thanks in advance.

DAVE

 

you would have to run LT1 t56 with yours. The clutch systems on them are less than par. No aftermarket one's have ever done well. I'f your not going to be putting slick on it then a stock vette clutch may last better than you think. The mods probably won't be that much to do. You will need bucket seats though for the shifter to clear due to the rear location of it.

 

Who said that? More and more of us are putting T56's by the minute.

 

Thanks for the replies. What are the major differences between the LT1 T56 and LS1 T56?


Well, I admit, I didn't exactly read through all the posts. I believe I may have gotten caught up on one regarding a 4,500 lb vehicle or something. Good to hear this swap is becoming common. I'll do some more reading.

Thanks again.

 

The bellhousing is completely different. And with that comes a different clutch, PP and flywheel. With that said the output shaft is different too. So pretty much nothing that's not internal is interchangable except for the shifter. You NEED one off an LT1, otherwise you'll be looking at an expenssive adapter plate.