1hotlt1

iTrader: (1)

All make it short... what type of valves should I use for stock lt1 heads? + am using nitrous... thanks Guy's.

food nd cars

valves shouldn't be a main concern unless you are planning on using a massive shot.
I would be more concerned with you bottom end. Your stock rod bolts, pistons, rings, even head gasket.. Also if its for a build make sure your cam goes well with nitrous and that your fuel delivery is on par as well as your tuning.

Mystery Bird

iTrader: (7)

You can get away with 2.0 intake and 1.55 exhaust on the stock seats with some grinding. I used Manley race flow.

RamAir95TA

iTrader: (2)

Stock.