1995 GMC SIERRA SHORT BED MARK IV 454 700R4
Recently got a set of PCE281.2034 Speedmaster heads. They are on Summit for $1,225.00 for a pair. I checked them over well. Casting seems flawless, bolt and spark plug holes all in alignment, with gaskets, and all threaded properly. They do not come with push rod guide plates or rocker studs. They do come with single springs with a dampner, not double springs as advertised. Quality springs with seats that fit over the bronze guides should be installed. That, along with setting spring height. The major surprise I got was that they were advertised with 119cc combustion chambers. I cc'd them twice to make sure and it's actually 127cc chambers. That will bring my compression down from 9.7 to 1 to 8.9 to 1. Had 116cc chambers on heads I was going to use. I wanted a streetable engine and 8.9 to 1 is great. The GM 454 HO engine has 8.75 to 1, along with an almost identical cam as the one I'm using. My dome volume on the 454 is -15.5cc 4.00 stroke. I will keep you informed!