What is the optimal spring pressure for TR224? Thanks.
My ARE heads had 130/305 (seat/open) pressure, but the valves were heavy as hell and it was insufficient.
My GTP heads first came with 918's setup at 130/310, but then I had double springs (987's) put in and I beleive they are now at 150/310.
So....300'ish open pressure looks to be what thunder racing is using.
</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I have stock lifters and my open pressure is @360 lbs. at 0.560 lift. I need to find my notes to find the exact lbs. figure. They are MMS springs.



