B.W. - I believe what you're saying about the differences in valves between the M. and S.M. But from what I researched, when they did the production change in '56, they did away with the Meteor and made only the S.M. and all the valves and heads are identical between the S.M. and Constellation, and even the early Interceptors based off of the 700cc platform. I have spoke with Richard at Hitchcock's over some early morning conversations a few different times. Speaking with him (he seems to be the most knowledgeable person on the Twins there) and Tom (Ace) here's what I have decided:
First, in order to get anything significant out of these heads they will need some major work and custom parts. I'm leaving all that to Ace and Mondello's as I feel my lack of knowledge in this department won't be much help beyond saying "Yes. That sounds good." or "No. I don't have Bill Gates money."
Second, there apparently ARE clearance issues with fitting bigger cams lobes into the twin engine cases. Upon further investigation, it turns out that the Interceptor Series I "R" Cams have almost the same identical lobe profiles as Ace's 357 Magnum Cams. So we are going to try those out first, see how the motor goes together and run it for a season. If it feels like we're still not getting enough, then I will consider sending out my cams to have them reprofiled for the next race season.
And Third, using either the Aisin AMR300 or AMR500 supercharger is going to be the most efficient cost effective way to build the kind of boost I want. After chatting with many different racers on the land speed racing forum, there was a real concern as to whether the modular cast crank will be able to hold up past 8,000 RPMs. There's a lot of controversy over this, so I'm going with the advice of other racers and am going to keep the redline RPMs closer to 7,000 RPMs as I don't want to burn up my brand new motor in one session of racing. If I use a turbo, I'll only be actually building boost for about 2,500 RPMs at this redline and there would be a lot of wasted power. By going with the supercharger, I'll be able to build boost right off of idle and continue building boost all the way through the entire RPM range. This means much more power down low and eliminates the need for HAVING to redline at 8,000 RPMs+.
Scottie