whats the best performance upgrades I can do to my l03 305tbi, with 29,000 original miles...looking for around 300hp, and lots of torque, its an automatic car, 1991 rs, not iroc clone, its iroc tribute
also whats a good street gear for better performance without killing mileage, has 273s now, car is bone stock, other than visable things, like decls, emblems, hood, wheels, and stereo system,
has kyb suspension, f41, 17 ridler staggered wheels, 8s and 9.5s, with federal 245/40s, and 275/40s
rides great, drives great, cold air, hot heat, just need more power, and a good thumping exhaust sound, not really wanting to swap heads, and no ls swap, maybe good cam, intake and carb?
what would u guys do???

300 hp out of an L03 without ripping well into the motor (and spending a pile of cash) isn't going to happen. You would be miles ahead to just toss the 305 and put in a L31 350 and a cam with full 3" exhaust.

What the heck is the difference between an IROC clone and a tribute?

You're posting in the wrong place, power adder is for turbo/supercharged/N2O questions.

300hp at the wheels or crank? Gears depend on use. In an auto car, you'll feel a converter swap more than anything else.