i have a84 camaro with a 350 with edelbrook rpm intake ,falt top piston , 480 lift cam ,holley 750. i put a set of trickflow heads on it yesterday and nowits backfiring threw the carb when u give it gas

 

Since you just finished dismantling the top of the engine, make sure the distributor is not out 180 deg, and you have set the valve lash correctly so that no valve is hanging open.

 

o lush to 1/2 roundand it runs but u give it gas and it backfires and is very weak what house should it have with that set up

 

horsepower should it have

 

I wouldn't worry about the HP till the backfire is fixed.

 

well for one thing that 750 you have on it is way to big it actually slows down the air going into the engine most 350 at 6000rpm only pull 625-635 cfm of air and that also could be the problem with the backfire i built a 355 with a bigger cam aluminum heads and every thing and i had an edelbrock 750 and i couldn't beat a stock stang gt so i put a holley 670 street avenger on it and i beat my friends 2001 ws6 trans am (with exaust and programmer) by 2 lengths and i had three other peoplein the car with me i am serious it is like night and day

 

It's backfiring because your timing is retarded too much.

RM

 

I agree with HotRodGuy. I would try a 650 cmf carb. Sounds to me like you're having a lean backfire caused by your air to fuel ratio going too lean when you whack the throttle blades open. The air rushes in imediately, but the low venturi effect ,caused by the large carb, does'ent pull fuel from the primary jet hard enough to cover lean spot. If it is a holly carb, you might try changing the primary power valve to a higher number. This will change how soon the power valve adds fuel when you crack the throttle open. This might cover up your off idle lean condition. One more tip. Buy a book on carb tuning for detailed instruction on how your carb works. GOOD LUCK!

 

Good greif man! You want somebody to buy a book and learn by reading it. That is cruel. lol

 

I was starting to answer this but I think I was typing what pete first said lol. What about the power valve blowout? Did you install the cam when you installed the heads, is it degreeed in. Depending on the carb it could be too large but going by a cfm rating I dont think 750 is to large especially with a dual plane manifold alot of 350s came with quadrajet 750s with less cam and smog heads. Borrow a carb and see if it acts the same. Also double check the plug wires to make sure they are not crossed up.