Well folks im picking up my ls1 monday. the questions of the day is should i go with a t56 or 4l60 auto? the car is a auto car and I have 373 gears, posi. mainly used on the street. I SHOULD ADD I HAVE DISK Brakes

Do you like shifting? I have a 2009 Pontiac GXP with a TR6060(newer version of the T56) 6spd and a LS3 with a 3.70 posi rear end. I love it. Granted this car is much different than a 1st gen but shifting gears is shifting gears.

It all depends on what you want to do. A 4L60 may be easier to physically install and maybe cheaper in the long run since you already have an auto in the car.

With a T56 you will need: clutch pedal, hydraulic clutch set up, a clutch, flywheel, drive shaft shortened, shifter handle among other things. You will also most likely have to alter the hole in the floor for this trans but am not sure. So there are some big costs involved. If you are looking to use a used T56, becareful what you get since most used ones tend to be trashed. Rebuilds are not cheap. I would go to LS1Tech.com and check stuff out there for more information.

i'm going with a built 4l60 in my lsx swap and a 4000 stall torque conv. my main decision maker was having to cut a hole in the floor and all that mess.

Go with what you really want. If you really want the 6spd, get it. Its not that hard to install, and I only had to drill one round hole in the floor. Used a hole saw & it was easy. I used the factory hydraulics hooked to stock 69 pedals. I fond I always regret not doing what i really wanted, and most of the time I end up going back and doing it anyway. Lets see some pics of the swap when you get started.

thank for the comments

@ z06vette right thats why im building another motor now. i wanted an lsx before.

Don't get a 4l60e unless you intend on keeping the engine stock. Unless they are built up, they can only handle about 350 hp. I'd go with a 4l80e if you're going the auto route. You may have to change the flex plate and add a GM spacer, reprogram your ECU and change a couple connectors in your harness, but the 4l80e is light years ahead of the 4l60e in terms of durability.

rp0029 thanks for the tip i strongly leaning to the t56

The 4l80 is super strong and its also bigger than the 60. Some say its actually easier to install other than the trans lines but a 90 degree fitting and a bfh should solve those problems. They are also a little more expensive and longer. I went with a 4l65. It was cheaper and my car is an auto and my wife wants to drive it. The 65 has 5 pinion planets instead of the 60s 3. Put some new clutches and a vette servo in it and you should be fine. I figure if they haul 400hp plus Denalis around they can prolly handle a first gen. I got mine rebuilt but not run and cheap. My 74 is a stick and I dont care if my wife wants to drive it. It will be a 5 speed.