my 350 (249hp@5k, 304ft/lbs@3.5k) with cast iron 72cc heads, cam (hydraulic) lift 0.39"/.41" duration @.05": 195/202 is a definite dog, but you get what you pay for. anyways, if i drop a xe262h cam in it like someone in another post suggested, how much of a hp/trq increase could i expect? the site for comp says anywhere from 20-70% increase. what do you guys think? thats a pretty big span for guessing. if i were to get the smallest gain possible(20%) i would be at 298hp. something doesnt sound right. edelbrock's performer plus power package (cam, intake, heads, carb) is supposed to make 310hp. so am i missing something here? how could just a cam swap get me 10hp off from the whole power package? would i even see a 20% increase? my heads are &%$@! someone please set me straight here.

 

What exhaust is on your car?

If you still have the stock exhaust, then there's a huge part of your problem. GM didn't rate that motor with it hooked up to LG4 exhaust. IIRC Edelbrock's "power package" was tested with their headers too. You will never get results anywhere near your engine's true potential as long as that drinking-straw-sized stuff is constipating your motor.

If you still have the LG4 exhaust, rip every piece of it off from the heads to the street. Replace it with some sort of application-specific headers, cat, & cat-back for some other car, such as a 89 350 TPI with single cat or some such. DO NOT replace it with ANY parts that are the correct ones for your particular car, as they will all have to retain the LG4's tiny little Y-pipe size, which is where the problem lies.

 

i was planning on getting headers for my 350. I know that the performer package had headers, carb, intake, heads, cam, timing chain, etc. and it only made like 310hp. But, if you were to take my motor 249hp and add a xe262 cam (which claims that you would see at least a 20% increase in horsepower) i would have ~298hp. only 12hp lower than the performer package. Now, it just doesnt seem right to me. so what i am trying to ask is, i could keep my stock 72cc heads, put in the xe262 cam in, add a performer intake (or whatever), add headers, and id have close to 300hp? wow, that seems to be alot cheaper than buying performer heads, performer intake, performer cam. If that is right, id spend approximately $200 for 298hp instead of ~$1500 for 310hp. Tell me if im right cuz im still discombobulated.