35% off SpeedMaster
I just got my Speedmaster heads this week. I got the cheapest assembled version. Took them over to a buddy of mine today and had him do a visual, as he used to have a engine shop back in the day. I mentioned the rather small spring package and he went into a box and pulled out a brand new Z28-350 spring and retainer and it was identical. Hence the .500 max lift. These also have 11/32 valves. An Elgin Z28 spring kit is about $55 bucks, lol. Chevy cheap. I installed a set of 273 rocker arms, and the clearance is fine. But the spark plug counter bore.....well its missing when compared to stock LA heads.