Basically trying to see if i can locate heads to increase the compression ratio on the 403 we are building. I am looking at 5 heads but obviously they need a modification to bolt up to the 403 and i would like to retain the 2" intake.

5 heads - we need that

Also, we are looking for a local machine shop in Chicago to help.

Nic

 

Not all #5 heads are W-31 heads. The vast majority are not. Any # 4 thru 7a head will work for you if you are willing to install the larger intake valves.


If max compression with stock heads is your objective find a set of 1967 #4 heads as they are they only 64 cc chamber SBO head.

 

You will have to drill out the head bolt holes on any early number head. I have some good core heads. I could help you with valve job or any other head needs. Shoot me a PM.

 

I have pretty much every # small block head ever made. As stated above the W-31 used the bigger valves in an otherwise common head. We raced a '70 W-31 in Stock Eliminator years ago and, when necessary, would have our machine shop install the larger valves in a regular head without any loss in performance. If nothing closer works out or if you know anyone coming down to sunny South Florida, I can provide you with good cores or complete heads, ready to bolt on. I would need some lead time for the complete units. Thanks, Bob.