I've got a 351w that I bought from a local rebuider. My questions are 1. What kind of pistons do you think most rebuilder use. I had a head off a while back and the best i can remember I think it was a flat top. I don't remember even seeing eyebrows on the piston, Would this make my compression higher?
2. I have a set of DOOE windsor heads I'd like to port/polish. If I used these verses the newer heads that's on there would that increase my compression even higher?
3. I've had some problems such as spark-knock, rough idleing, pop in the idle and such that I've been fighting for a while. I know alot of it's the timing advance or base set at (6btdc). Knowing the rebuilders said a new cam was installed, he could'nt tell me the name brand, I'd think they probably don't use a high quality cam, could it be a poor gring giving me some of my problems?
4. Would I feel a significant increase in performance using the DOOE heads ported/polished verses what I have now. The current heads are newer with the square water passages, came off an egr engine.
Alot of questions, maybe some food for thought.
The engine has a elderbrock performer with a 600 Holly, MSD 6, stock exhaust. Pushing a c-6. 3.25 rearend in a 71 f100.
Thanks for any sugestions or comments.
Clint

 

You shouldn't be getting any spark knock at 6 BTDC with that combo. I would suspect a problem with your distributor...I had the magnetic pickup go out causing the same problems and finally dropped in a beautiful MSD dizzy...not only solved my pinging, but my engine ran 20 degrees cooler to boot...you should be able to go betwee 15-17 degrees of advance before you start pinging...