compression with 274cam

The XE274 requires double springs too. I went with the XE268H because so I wouldn't have to deal with double springs.

FWIW, I am running 10.6:1 compression on 89 octane mid grade gas, might even run on 87 but haven't tried. The key is the zero deck KB107's, closed chamber magnum heads and 0.040" compressed head gasket.