Kevin, you're probably right - there is a direct and linear correlation between what I see as free length and seat pressure at the installed height spec. Also, the factory does give both a free length standard and minimum spec, but only provides the one rate spec of 74 lbs at installed height.

I'm pretty sure that heat trashed these. I measured one spring from a Diamante head and found it a lot closer to standard spec. Among all of the heads I have here, I might even be able to come up with a decent set and avoid buying new ones.

I just looked closely at the heads and found a bump on an area that I "thought" was just inside the fire ring. I sanded on it a bit, then grabbed the dremel to level it and promptly dug into the quench pad a little too much - particularly when I put the gasket on it and found it was under the fire ring. <img src="/forums/images/graemlins/scared.gif" alt="" />

So, I'll dig out a reserve set of heads and start porting again. <img src="/forums/images/graemlins/rolleyes.gif" alt="" />

I had some trouble getting the cams where I want them on these heads with the new block. The offset bushings work about as they should on the 0,4,5 and 6? bushings, but the 7 and 8? bushings go whacky and roll the cams forward too much. Perhaps it's a difference in geometry of the Chevy pin location offset from cam center. Maybe if I have a set of full-thickness heads, I can get the cam timing closer to what I want to see.

Frank