GMpart number for ZLX heads

[Chevy454]

I believe BKH's '69 did come from Yenko with an L-88...any others?

[Stefano]

Based on 'The Complete do-it yourself guide to top Street Performance' 1972. "The ZLX 454 Phase III...dyno rated at 575 hp. The ZLX designation indicates the use of open-chamber cast-iron heads, first introduced to the speed field a couple of years back by Rosen on his personal race car. They have since become a performance standard.", Executive Editor, Martin L. Schorr

[JoeG]

Just some extra info---1969 L-88 opened chambered blueprinted 427 ZL-X---650HP---.585/.605-PhaseIII cam 12.8/1 piston--choice of 850/950/1050 Holley carb- VERY SPECIAL M/P competition engine.---JoeG

[Schonyenko2]

I had a conversation with a person who should know ,that told me that before 71 any open chamber iron head, as in ZLX came out the backdoor of GM to only a very select few people. The part # will not appear in any GM parts books as they were experimental iron versions of the ZL1. Comments? Schonye

[JoeG]

The person you talked to has good info as only a few sets of ZL-X cast iron heads were produced for drag evaluation testing 1969 ---I don't have any GM # for these--JoeG

[68l30]

ZL-X heads Motion # 3946028-70 List for $395.95 (pair) in 1970.......

Steve

[JoeG]

68/30
You are correct, they did have a B/M part # starting in '70,-- but still no GM. part #, at least officially,but there had to be a unofficial GM part# for the few special people who got them [img]/ubbthreads/images/graemlins/beers.gif[/img]