Interesting GM Aluminum Heads Experimental/Prototype Big Block Chevy
 

I recently picked up this pair of factory Big Block Chevy aluminum heads that came out of an estate. One head is casting number 334112 and the other has the 3946074 casting as well as the casting 0334112 as shown. The wife of the gentleman that passed away said her husband called these his "cheater" heads. The look the same as 3946074 heads to me other than the combustion chambers being slightly different. I imagine the combustion chambers were smoothed and has the exhaust unshrouded after they left GM. Has anyone ever seen this casting number before?


Thanks,


Jason

What is the casting date of the 074 head? A part number starting in 0 is experimental. What is that date?

3946074: ’69 rectangular port, open chamber, 2.19- and 1.88-inch valves, aluminum. Used on 427ci L88 and ZL1 engines.

3946074: ’71 rectangular port, open chamber, 2.19- and 1.88-inch valves, aluminum. Used on 454ci LS6 engines.

https://www.chevyhardcore.com/tech-s...-head-id-0219/

Thanks for the replies. The head with the 3946074 and the 0334112 casting looks to be 11/17/67.

Jason