I was wondering what kind of plugs are recommended for an 88 IROC 5.7 L engine. When I put my engine together I used AC R45 TS plugs,gapped at .035.I have seen 43 TS or something like that on my friends 91 firebird. What are the right ones? It is just going to be a daily driver so I just want to keep everything as factory as possible.

 

If your engine is stock, you can't go wrong with OEM plugs. If you want longer life you can substitute platinum or iridium plugs. Different year engines use different plugs, so you can't really compare with what is installed in some other engine.
What is really important is the right plug for your particular engine. This includes correct reach, gasket or no gasket design depending on how the plug hole is machined, proper tip design, and heat range for your particular engine. Part houses have charts for the correct plug for just any stock engine.