I will also not get into the fact this engine also gained 27 hp and 6 ft/lbs from a valve spring and retainer change. Lets just say I had a local machine shop pickup and install 2.02/1.60s in these heads and somehow ended up with 0.100" longer than stock valves and shimmed stock springs that did not even have 70# at the seat. With 1.7:1 rockers my small 395' cam had .489/.511 lift on stock Vortec springs at a 1.8" installed height. Between 5,100 and 5,300 it lost more than 20 rwhp mostly from valve float. I went from 230 rwhp to 257 rwhp changing to LS6 springs and Comp 787 retainers and using hardened .030" and .015" shims stacked to get to a 1.755 installed height.
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