Vortec Heads????? I Need Info.....

[UD LOSE]

I need to know how the '87 350 vortec heads flow. Are they comparitable to "camel-humps"? What (cam) lift are they good up to? Can they be milled & if so how far? Trying to help a friend get his Firebird running like a FORD!! =) Thanks for any help! Mike

[89IROC&RS]

um???? 87 vortec heads?????? you mean 97 vortec heads. vortec didnt come out till 96 to the best of my knowledge. and those heads outflow entry level bowtie heads, so they piss on camel hump heads. they have a 61cc chamber, 170cc intake port, 1.94/1.5 valves stock. and can acoomodate up to .470in without modification. compcams offers a "beehive" spring not unlike those on the LS1 engines that will allow you up to .550in (?) lift without modifying the heads. to use standard dual spring springs, youll have to cut down the valve guide, both in height and diameter, and enlarge the spring seat in the head. when getting a pair of vortec heads, only get those ending with a 062 in the casting number, they are the performance heads, found on 96-1999 tahoes, suburbans, silverados, and GMC equivilents. those with a casting number ending in 908 are used in box vans and such, and have exhaust ports that cannot be worked, and wont accept oversized valves. the casting number is in the rocker vally in the head. a 8 digit (?) number that is easy to find. just look at the last three digits, 062 is a good buy, 908 is a paper weight.