[Nsgrn]

Did these heads have oil galleys in the rocker studs?

The machinist doing my cylinder heads is telling me that one of the pressed 3/8 stud threads is chewed up. But he said all the intake studs have holes in center of the stud..
I am unaware of this. First pre 67 Pontiac I have built. Any help appreciated.

[b-man]

Yes, all 1964 and earlier heads except 9770716 GTO/421 HO heads and 421 SD oiled through the rocker studs instead of through the pushrods.

[John V.]

Didn't all '64 heads including the 9770716 heads get the same press in studs (exhaust and intake) with the hole in the center?

I know about the oil gallery difference but asking about the studs themselves.

FWIW, both the pushrod oiled design AND the rocker stud oiled design fed oil from the hollow pushrod to the rocker pushrod socket.

For the pushrod oiled design, a small hole in the rocker allowed some oil to pass thru to the top side to lubricate the rocker ball area.

In the rocker stud oiled arrangement, oil from the pushrod only oiled the rocker pushrod socket area, no hole in the rocker.

For this design, the rocker ball area was lubricated by the oil that came up thru the hole in each stud fed from the pressurized oil gallery in the head.

Somebody smarter than me could tell you for sure, but seems to me that the "stud oiled" early heads can be "converted" to pushrod oiled simply by swapping the original rockers without holes for the later model style rockers with holes.

I'm not aware of any difference in the push rods, you'd have to check that out.

All '64 blocks had the oil gallery feed passage. With the 9770716 heads, this passage had nowhere to feed.

If you make the conversion, with the 9773345 (or 4 bbl 9773394) heads, I think you would want to block off the oil gallery feed passage in the block so that you aren't lubricating the rocker ball area from two locations.

I don't know if there are any other issues to worry about, but I've not done this or heard of it being done.

Just suggesting that it could be a way to go and if it is, I imagine some engine builders here would be familiar with it.

I really can't see why it wouldn't work though. I believe Pontiac determined this was a better way to lubricate the rocker ball area as they went to this arrangement exclusively for all heads after '64.

If you need a set of 9773345 heads, I have a set off a '64 389 that are looking for a home. I'm near Jax so not real close to you, but PM if I can help.

[b-man]

The hollow press-in studs were used all the way into the early '70s even with the elimination of stud oiling, using up old stock one would logically surmise.

Both the intake and exhaust studs have the oil passage drilled.

Simply bolting down one of the 9770716 heads would block off the oil passage coming from the block, the head gasket will seal it off.

[John V.]

b-man, that's what I thought about the studs.

I understand about the 9770716 heads blocking off the oil feed passage from the block and tried to indicate as much.

What about my idea to convert his stud oiled heads simply by changing to the rockers with the holes and plugging the block feed hole?

Will it work or am I missing something?

[b-man]

Plugging the block feed hole is all that's needed, if I'm not mistaken the factory had an aluminum plug that could be driven into place on the block deck.

I've tapped them for 5/16-18 thread and plugged them with a socket head set screw.

[Nsgrn]

B-man, John V

Thanks for the good info. I had no idea the 64 oiled through studs to ball pivots. I bought this engine as it was year correct for my car. When I took it apart there was no way you would see that, as it sat since the 80's

Currently I have the short block assembled and complete. .040 bore 20/20 main and rods. Waiting on head completion.

I can plug the block. And I have a spare set of oil holed 1.5 stock rockers, then purchase pushrods. Is that what you guys would do if it were your build? Obviously Pontiac engineers thought it was a better oiling system.