[Paul Huryk]

Dave,

I will suggest the Global West RCAs and Control arms - have them on both of my 3rd gens. I do have an unused set of LCA lowering brackets if you want them - not going to use them on the GTA.

Front bar should be 34mm, rear 23mm on an IROC. Some have been known to have different bars - not counting if anyone did a swap prior in it's life too.

If you are absolutely sure the knock sensor is not getting set off by detonation - you can desensitize it a bit by putting some teflon tape (2 or 3 layers) on the sensor threads and put it back in.

Nitrous kit is easy on those cars - have done about 10 systems over the years. Do get a trans cooler if you don't have one... Nitrous is rough on transmissions.