Rear gear selection for LS engine, opinions please.

[Tim john---]

Good afternooon all, I would like some honest opinions on rear gear selections. Car in question is a 69 Firebird convertible with (will get) a stock 2004 GTO LS-1 engine and most likely a Tremec T-56 magnum six speed. Car will be a very nice stock appearing vehicle with no track duty in mind (for now). Project is just starting to get off the ground, everything is disassembled. Car will be DSE mini tubbed (tubs currently installed). I have two rear ends in stock, a grey iron open (non-posi) 2:56 and a Nodular posi w/ 3:36. I have to alter one of the rears for the mini tubbs (re-locate the spring perches). The 2004 GTO's all came w/ a 3:42 with a six speed I belive so would I be best off with the 3:36 or step up to a 3:55 or a 3:90. Keep in mind this car is not being built for track duty, just a really fun street car with stock 2004 GTO performance with reasonable fuel mileage. Thank You.

Tim john---