Updating this post. Turns out I had the opportunity to take the heads off and took the 1000 mile old 99838's to Paul K for a pressure test. He came up with 150 lbs at 1.8" which is pretty much what the catalog specs them at. Either way, since I had things apart and the motor will likely see some higher RPM this time around, I took the opportunity to upgrade to Crower's 68380X2 spring. It turns out this spring fits perfectly in the same space as the 99383 and depending on what installed height I want to run I can use the retainers Dave set my heads up with and I have sufficient seal clearance etc. Paul K tested this spring as well and it produced 210 @ 1.8 which puts me at 470 over the nose. Crower says it should be at 197 @ 1.8 FWIW. https://www.crower.com/valve-springs...-w-damper.html
With my combination of retainers and locks, I can achieve pretty much anywhere between 173 and 210 lbs (calculated) on the seat. My coil clearance is .09" at the 1.8" installed height. What do you spring experts suggest for a seat pressure?
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71 Formula 433, Splayed cap 400 block, 4" stroke Scat forged crank, 6.8 Eagle rods, custom Autotec pistons. SD 295 KRE D ports, Old faithful hybrid roller, Torker II, Holley Sniper Stealth, Tribal Tubes, TKO 600, 3.73 Eaton posi.
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