I got a 5.3 gen III head for the valves/springs/retainers for my 2.5 race engine and since my head is still on the racetruck, i decided to see how well at the stuff fit in the buick head. Intakes are 1.89 and 8mm valve stem, and in the stock head i got 1.65 +/- a little as an installed height for the intake, the exhaust looked like it wasn't seating fully (bigger valve job, although they are both supposed to be 1.55 ???) The beehive springs installled at 1.800 in the 5.3 heads an i'm pretty sure the specs are really close to the comp 26915 beehive - 105 @ 1.800, 1.085 coil bind. So at 1.65 ins. ht they should accomodate a .510 lift. (i'd check the actual specs and lb's but i don't got a spring tester and its 10 at night) My question's are - whats the stock valve spring height on a sbb and how much meat is available to cut the seat down a little to see if its possible to bring the spring hieght to a slightly more acceptable level for more lift cams. These are really nice parts, nice flat one for the intake and a good tulip shape for the exhaust. They may not be aftermarket but they are cheap and really close to the right size
