mystery numbers bb heads kA

[saved2az]

kA heads 413191 the side of the head that mates to the intake manifold after assembaly looking down at motor there is a 1/2 inch of cylender head that you can see under the valve cover and obove the intake mainfold there is lege there and i have the AX130 STAMPED DOWN THE HOLE LENGHT OF THE SHELF ANY ONE GOT ANY IDEAS

[svnt442]

KA heads are marine heads and were also used as service replacment heads on W30s.

[grandma'sH/O]

K heads are big valve heads for marine use. Ka's are big valve heads made to run unleaded fuel... I've always wondered about the small letter A on Olds cylinder heads like Ca, Ga, Ka,. I think its for unleaded fuel, but why is there and A on some C heads?

[svnt442]

It's done for a minor revison in the casting and has nothing to do with leaded or unleaded fuel.
1971 G heads were the first with "hardened" valve seats for unleaded fuel. There was a slight revision to the casting in 1972 hence the GA.

[Olds64]

Weren't Ka heads also used on the 455s available in motorhomes? Or was that a different casting?

[Eightupman]

Originally Posted by Olds64

Weren't Ka heads also used on the 455s available in motorhomes? Or was that a different casting?

Yes. Ka heads are for "recreational" use. Meaning marine, motorhomes, industrial ( irrigation pumps used 455's) and then they were the factory warranty replacement for W30 motors.

John

[joe_padavano]

K and KA heads were marine and industrial applications. They were never factory installed on any production automobiles. I also do not believe that they were factory installed on the GMC motorhomes, either, but I don't know that for sure. All Olds heads manufactured after 1970 have the induction hardened seats.

The fact that the K heads were "factory replacements" for W-30 heads does NOT make them equivalent. After 1973, the only BBO heads in production were J and K. J heads were listed as superceding all prior low-perf heads and the K heades superceded all prior high-perf heads. They were the best available, but not equivalent.

As for the stamping, since these heads were never factory installed, it means nothing. It could either be related to the aftermarket installation of these heads in a boat or other use, or it could be some machine shop stamp.