I currently have a 95 z28 camaro and have done a few minor performance mods. My first question is, will upgrading the stock 48mm throttle body to 52mm give me any performance gain without head or intake porting. Secondly ive been hearing that upgrading the rocker arms to 1.6 will give you a performance gain between 10-15 horsepower, any feedback would help.

 

yes you will gain some by doing 1.6rr, and the stock intake can handle a 52mm tb without porting but you wont see much of a gain

 

I agree with what Alih said. Personally I don't think you should screw with anything other than a 58mm TB after you've done head/cam work to the car. A 52mm isn't going to get you much and the stock TB is good on flow until you're making ~350 RWHP. The 1.6RR will get you a little increase in HP, but not too much. I would suggest looking into a nice exhaust system (headers back) instead of the mods you listed.

 

If you haven't done it yet, one of the most cost effective mods you can do an an LT1 Camaro is to get a real cold air intake. Besides bringing in more cold air it eliminates the restriction on the intake that GM put in to hold the power below that of a Corvette. This mod is worth about 15 HP. Another cost effective mod, as 95Silvr indicated,is a header back system. It eliminates the restrictive section of plumbing in the stock Y pipe, and where the exhaust pipe is routes over the rear axle. These mods will make all future modsmuch more effective. As for the 1.6 rockers you are not going to see a 10-15 HP increase unless you go to full roller rockers that substantially reduce friction. Also with the 1.6 rockers you should upgrade the valve springs to avoid valve float and bouncing.