I bought an 85 Firebird from a buddy of mine who bought the 350 block & heads from me to swap into it (before I bought the finished project for half the money he spent? <shrug> he likes 4x4 trucks better). Well, I didn't bother running the ID #'s on the heads before I sold them, and now they've been to the porting shop courtesy of my buddy, and they're on the car. Well, my 350 with new pistons, rods, cast crank, 10:1 compression, 280H Magnum cam, Perf RPM manifold+ 750 carb has one problem:

The heads came from a 77 305 (376450 casting, 262/265/305, 1.74/1.40 valves originally). Everywhere says they royally suck. I agree fully, with a 16.4@92 (2.8 60') to back up this. Sure, 92 mph is good for a mid 15, so the ET's not the problem. $2000 worth of motor work and it's a 16 second ride!

I only have $300 or so to spend. I can get Vortecs used for a little over this, but my manifold won't work. I could buy iron L98's for CHEAP. I could get 305 HO heads by the truckload too. There's a good U-Pull-It salvage nearby I can get heads for 30/ea, what cars should I look for?

But what should I do??? I am so disgusted by the performance. It's really really slow. The ride I smashed ran a 12.96@103 (93 LT1 Z28). It'll be a year this Saturday since my wreck, and I was hoping that MAYBE I would be near the same perf. as last year but I'm not! I was hoping this cammed 355 would be my salvation and it's not.

Thanks

 

I would guess you are over cammed for those heads...the vortec heads would have to be modified to use with the cam you have. I would look into a set of aftermarket heads....By the time you upgrade your other options....the price of ...lets say, Pro lightnings, Are about the same.

 

Of all the heads that you listed, the L98s are the best starting point. Then port and polish them according to the instructions at the end of my sig. Should get you into the 13s

 

Find some #416s... 1.84/1.5 valves, but thats easy to change, AND they have 58cc chambers.. so they make some really good compression.

Easy to find too... all 305 f-bodies and probably most other 305 powered cars and trucks.