how much horsepower does my 1991 Z28 with a 350 bore over 30, roller tip rockers,headman shorty headers,?

It's less than 200 at the wheels most likely. The long runner intake manifold makes lots of torque but will not make HP. If you shift the car at 5000 at the track and then move the shift point up to 5500 on the next run, you'll see that you'll cost yourself close to a second. On the dyno, that intake manifold falls off a building at 5000 no matter what you do in the head and cam department.

There are lots of induction restrictions, but none of them really mean anything because the manifold is so useless after 4500 that they're trivial.

I've dealt with lots of L98's and owned a few as well.

Shon - the critical information is missing. What do you have after the headers - what exhaust mods? Are your heads stock? Camshaft stock? If you know what you have there, it means all the difference of about 100 horsepower on the "brain cell dyno"!

And enough of these guys talking smack about the TPI cars. You're car had 250 stock. With just the headers, you're probably around 260 if you're still pushing into the stock cat. If you've done all the right exhaust mods, you're probably 270-280, and ported/aftermarket heads, and performance TPI intake would put you at or over 300 hp. That's some pretty fine numbers from such a terrible engine, don't you think?

Your info is not there to give a good aswer.

Is that the stock engine?,

Is it carb'ed, TBI, TPI?

It was bored .030" over but what pistons did you use in it. Are they dish, flat top, or dome? What CC valve relifes are in the pistons?

What head gaskets did you use on the rebuild?

What heads are on the engine?

Are the roller tip rockers 1.5, 1.52, 1.55, 1.6, or 1.65 ratio?

What tube size is the headers. 1-1/2", 1-5/8", 1-3/4", 1-7/8"?

Are the colletors 2.5" or 3"?

Are use using a compression bent Y pipe, aftermarket mandrel bent Y pipe, or are you running dual exhaust?

What size is the pipe?

Sorry if I'm coming off as stand off-ish but all that above info is needed to get even a good guess of power

Now I will tell you this.. The overboring might gain you 2-12 HP depending on compression you now have

The roller tip rockers won't gain you much eaither. 1-3 HP if it's 1.5 ratio. 1.6's might gain you 10 HP

The headers will gain you around 15-25 HP

So if you have a stock L98 350 TPI with 9.3:1 compression making 245 HP stock

If you used a flat top 4 vr piston, .030" over and fel pro 1094 .015" thick head gaskets you will have 9.95:1 compression now which will gain you about 5 HP

I would guess 272 HP at the crank, thats about 223 HP at the rear wheels

Is the 350 the stock engine? Is it still TPI? It had 245HP bone stock. So it depends on a lot of different factors, such as the type of pistons you have in it, the compression ratio, etc etc.

Being very conservative, I would say that your Camaro has at least 275HP. It could be much more than that, but again, it depends on what kind of pistons you have, the cam, the exhaust, etc. At the very minimum, your car has 275HP.

what kind of fuel delivery do you have? carb. or fuel injected, if it's been bored what type of pistons? how many miles, without knowing any of this stuff I would say your pushin about at 100 to 115 horsepower, so go and tell all your friends that you have alot and by the way you should stay on the porch and sell your car to someone who knows what they are doing before you get hurt!!

110

Anyone want to show me the math and walk the talk? Come on don't be shy.

Around 245 HP @ 4800 RPM.......

Bring it to a Dyno, then you will know.

12/cant believe this about the hot rod books/i seem to recognize this type of post/by the way what is the cam duration???better get that book out /are the porting and polishing done by by pro??if so who?what about the balancer??also i see you are a very very new person to this site but i suspect you were here under a different name?????