I'm about to start swapping a t56 into my 82Z that had a 4l60E behind an Lt1. I think I have everything but I still have a few questions.
1) I bought a new LT1 flywheel from GM. Do I need to have this balanced for 0/0 or balanced to the old flex plate behind the LT1. The existing install with the 4L60E would spin to 7K without as much as a flutter .

2) The second question I have is cutting the hole in the tunnel. Should I premeasure and just cut the hole or remove the shifter and put the trans up there and cut around it (drill alignment holes from the bottom and cut from the top).

Any hints would be greatly appreciated.

Thanks

 

I'm not sure about the balancing, but I can help on where to cut the hole.
I didn't line up the shifter, I just took some measurements off my buddy's 5 speed Iroc and cut the hole 2" farther back from where it was on the iroc. I used the T56 heat bellows to measure the exact size and shape of the hole once I determined how far back it needed to be. When I put the tranny in, the hole lined up to the shifter perfectly. I wrote down the measurements I took on a piece of paper somewhere, but I'm not sure where it's at right now. If i find it I'll post it to let you know.