L89 Factory Heads

[Scott R.]

Curious if anyone has heard of late(Nov) 69 L89 cars coming equipped with the 074 open chamber heads instead of the square port closed chamber head normally used. The owner of a car I am interested in is sure his car left the factory so equipped but I cannot find anything to confirm. It is otherwise a nice 435 HP tri-power car but there would be a big delta in value if not. Thanks

[Patrick B.]

Re: L89 Factory Heads

There are no GM pistons that produce anything near the L-89 nominal compression ratio of 11:1 with these heads which makes it unlikely that they were ever used as a substitute for the 842 heads. To bad the heads have to be removed to see the casting date. The date is very likely later than the engine build date which would prove they are not original.

[Scott R.]

Re: L89 Factory Heads

There are no GM pistons that produce anything near the L-89 nominal compression ratio of 11:1 with these heads which makes it unlikely that they were ever used as a substitute for the 842 heads. To bad the heads have to be removed to see the casting date. The date is very likely later than the engine build date which would prove they are not original.

Thanks Patrick, Makes good sense to me