After ruling out other root causes (head gasket, warped head, standard Hardin exhaust manifold leaking, binding valve springs, etc...) I believe I am experiencing early (< 100 hours) reversion (corroded ss exhaust valves, foamy oil only in valve cover (not manifesting in oil pan yet), and three broken Comp Cams valves (two exhaust and one intake) on my 593hp, normally aspirated motors in my 1988 Formula 311 SR-1.
My gameplan is to replace my original Gil wet pipes with high rise HP500 Wet pipes (620-32330) and bump up my idle rpm 50-100 rpms. My play-doh investigation (see picture) suggests I have enough clearance (even at the reinforcing edge ridge/rib).
1) I am looking for 1st person experience with these high rise pipes and did they fit and work for you and/or if there is a better plug & play option out there.
2) Will the Gil "turbulator" ring fit/work/help?
3) Any other free/cheap modification/adjustments I can make (other than high rise pipe and raise idle rpm)?
Thanks,
Tom

Might get better traction over in the Tech section, Tom.

Any more news from the machine shop?

Good point (tech) and one broken spring (exhaust) on #1
Focusing on risers, etc...