Quote Originally Posted by LURCHBIOTCH View Post
Okay sounds good tech. I will get back to you when I have these measurements. I am guessing the best way to determine the spring pressure, seat pressure, etc. Is to just take them to a machine shop where they have the tools for that kinda stuff?
Also....
.....what kind of square bore carb do you reccomend?
.....I have read a few other posts by you and you always rec the Keith Black D dish pistons. Why are you so fond of these? Just my own curiosities.
.....Is it considerably better to use roller rockers as opposed to the stamped variety?
If you don't have the part number of the springs so that you can find the specs on them, remove one only and take it to a reliable engine builder in your area to be checked out on his spring tester. Comp specs the springs for this cam to measure 105 lbs at the installed height of 1.700" and 273 lbs at 1.250".

Square bore equals Edelbrock, Carter AFB, Holley, Barry Grant, etc.

I like the KB's because they are a premium quality piston and utilize a large flat area on the crown to mate up against the bottom of the cylinder head to produce an excellent squish of the air/fuel mixture toward the spark plug as the piston approaches top dead center. Check the large flat area on these pistons as a result of the offset D dishes as compared to other pistons that utilize a concentric dish. No comparison.

Roller tips on these aftermarket rockers are too small to generate a mechanical couple on the valve tip and have been shown to skid across the tip under high speed photography. Where these things shine is the needle bearing trunnion. That's where you are going to reduce friction to free up a little free horsepower and lower engine oil temperatures. In my opinion, Harland Sharp makes the best ones. Some of the first ones (Crane, etc.) were designed with the wrong geometry, but I'm told that HS has corrected this error. A line drawn through the pushrod axis and a line drawn through the rocker pushrod tip/trunnion should ideally be at 90 degrees to each other with the valve at half lift. Additionally, a line drawn through the rocker trunnion to the bottom of the rocker roller where it contacts the valve stem tip and the valve stem axis should be at 90 degrees to each other with the valve at half lift.

It has been said by some respected engine builders that you can pick up 20 hp in addition to lower oil temps with roller rockers (roller bearing trunnions).