Ken, check your e-mail.
I have an article from the April '72 issue of Hi-Performance CARS, featuring a '72 Chevelle with the ZL-X option. Also in the October '71 issue are ads from M/P showing the "Super Trick Open Chamber Cast Iron Heads" (Racer's Net... $395./pair). It shows a M/P Part No. of 3946028-70....... maybe NOT a GM number! (but worth checking)
Also a Complete 427 inch ZL-X engine for $1395.00 and the 454 version for $1995.00.
