Flat top. 1.627" CH. Use R42558 or M42558 rings.
7.4L / 454 OHV V8 16V Chev. 4.250" Bore 70-76
GM
7.4L / 454 OHV V8 16V Chev. 4.250" Bore 71-00
GM, CHEVROLET
GM454C-CH | 7.4L / 454 OHV V8 16V Chev. 4.250" Bore 70-76
CHEVROLET
GM454T-CH | 7.4L / 454 OHV V8 16V Chev. 4.250" Bore 71-00
CHEVROLET,
GMC