Poly heads

[Moparaddict]

I'm trying to see what i can do with my '66 belvedere without going to a bigger engine. i have a 318 poly and i wanna know what would be the best thing i can do to the heads just to make em breath better. i understand la heads wont fit and i wanna stay with the poly and if u know of any good machine shop in so cal i'd appreciate it thanx

 

[Dako]

Opening up ports (matching to gasket holes) is a good start. Cleaning up casting marks is another. Don't go crazy 'polishing' on the intake side as the heads need some turbulance to properly mix fuel & air. Larger valves can be installed also. Up to 2.02 on the intake and 1.60 on the exhaust. In stock form you have 1.84 & 1.56. There are many things to do to these motors. It all depends on how much you are wanting to get out of it and how big your check book is. Once mine is on the road I'll be looking forward to opening my hood to show off my old poly motor...especially to the 'non believers'. As I stated in your other post on the 66 70 Mopar thread, get ahold of Gary Pavlovich. Good luck!

 

[Moparaddict]

Thanks Alot. And your are right. There's nothing Like beating the big boys with a "small" block

 

[64plybelvwgn]

If you go to " 318 poly" on ebay you should find a pamphlet / book ( I think $19+) that will be more specific about HP updates for the 318 poly. Also if you look at the 62-65 Mopar site you'll find a gentleman named Gary P that appears to be the 318 poly guru. If nothing else, a good read.

 

[gto64gto]

I bought a new 65 Belvedere II with 318 poly and 3 speed. I think I had a 3.25 rear. I put on a 318 4 barrel intake (factory cast iron) a small AFB (I tried a 383 AFB but it was not as crisp), adjusted the valves on the thight side, put in a Hurst 3-speed floor shift, and put on dual exhaust with Corvair turbo musslers. The car really ran well. I wanted quicker advance timing so I filed out the advance slots in the distributor and stretched the advance springs with neeedle nose pliers. I don't know how much thought. That was in 1965. That set it on fire. I shifted a 5000. I could out run a 383 auto or 4 speed to 100. I never got out run. I never pulled the heads. You can make really good power on a low budget. I did. Hope this helps.