all I can say is choose your cam wisely and talk to an expert. I run 555's in my S&S 106, it came 10:1:1 compression. I added stage II heads that were milled to bump up compression to about 10:5:1. The CR compression was measured @ 182psi - I can see it being cranky when it gets really hot out - luckily I added manual cr's and my indy had to add a thicker SE headgasket just to keep it this low.

 

I've wandered the same thing on a 107" build and keeping My SE 254e cams.

 

Too much squeeze for the 204 cams. I'm putting together a 107 build for my bike, and the 204 cams will be one of the first things to go. The 204 cams work great in the stock 103 bikes, partly because the compression is right. You'd have to open up the combustion chambers to bring the compression down, but why do that when you can just run the right cam?

 

This is good info in regards to the right compression for the cams. I certainly want a to have everything work well together. So now I'm back to the FM107 or a 103 / SE204 combination.

Its probably hard to beat the FM107 kit as far as a good combination and price.

 

It's certainly a proven combination. Most of the big builders have their own favorite "recipes" that they use to build a performance motor. The best ones come from long hours of testing and trying different componants until you come up with the winning combination.

I don't think we've really found the best stage II 103 build yet. (By that I mean, which combination of cams and exhaust will return the best performance, keeping stock heads.)

If I was starting from 96 and wanted to build a somewhat frugal performance build, I'd shop ebay for a set of Andrews 54 cams, have my existing jugs bored to 107 locally, and run a set of whichever flat tops I could find for the best price. If you then use a 030 Cometic hg, you can reuse your existing stock pushrods. (base circle of the Andrews 54 is slightly smaller). If you do your own work, and don't need to buy a new tuner, you could easily keep your build costs well under a grand. If you're running a PCV from fuel moto, they'll send you a map that'll get you close.

 

my 103,255 cams.short block charlie head ported ,lg intake valve,10.1 comp,,save $$$ ,no more heat problem, just have 500 miles on new build,, phx az 112 heat