They held up fine with my 11.1:1. Went with them for the very same reason you state - 60 over 440 wouldn't allow the other gasket to work.

1967 Satellite, CNC Eddy Headed 500ci Street Mauler
(Dyno'ed @ 600 HP / 650 ft-lbs)

2016 Challenger Hellcat - Holy Hell
2012 Hemi Ram Sport Crew Cab
2011 Avenger, Pentastar V-6
2007 SRT-8 Charger (Dyno'ed @ 470 RWHP)
1986 Caravelle, 318, aka "Rosco", Back Road Burner!

ALL Black...Bad Boys always wear Black!