I’m doing this swap on a 1986 Camaro using a future T56 transmission. Should I buy third gen Camaro manual pedals or 4th gen pedals ? Which works best . Please let me know. Thanks in advance

Third gen pedals have longer clutch master cylinder travel.
The 4th gen pedals line up except 5th bolt up top.

On T56 swaps, I prefer to deal with OEM 4th gen pedals, cut the gas pedal off (if V8) and modify a bit to deal with bolt 5. This allows a "all stock" master and slave assembly to work.

I agree with using the 4th gen pedals and hydraulics. Cut the gas pedal off and use the 3rd gen gas pedal. The pedals bolt in just fine and I was able to get the upper bolt in without modifying it. Just had to loosen the mounting bracket to get the bolt started and then tighten everything up. For the brake and clutch switches, you'll need to use the 3rd gen switches with the 4th gen plastic threaded inserts, no big deal though.