I have a '67 Chris Craft 27' sports express with twin 283f (185hp) engines that are tired, leaking oil and water, and need to come out. I bought a pair of correct 327f's (CC's designation for forward facing inboards) that are rated at 210 hp., and thats with afb's on top. Id like to get a little more out of them while theyre out. Theyre 8 to 1 with 172 intakes and 75 cc chambers. Rated hp is 4000 rpm. My questions are:
1. Are the 172 intakes choking flow at 4000 rpm and what rpm are they good till in a 327?
2. Marina gas around here is 91octane, so if I go to a smaller chamber, like 60 or 62 cc, so the compression is 9.5 or so, would 194's help? Im staying with the stock cams, and yes the starboard engine is a counter rotator. I know theres a lot to consider.
3. Is there a link or list somewhere that lists full specs about each head so I know what heads to look for?
Notes: I believe the stock cams are good till 4500, so I dont mind twisting them a little more. Ill be putting hei's on them which is a noticeable improvement. I have performers with q-jets to use, also. I also considered 1.6 intake rockers if the 172's stay. Thanks!