Tom Canfield

Hello everyone,

I am working on refurbishing a pair of #7A (subcript 'A' from '72) Heads for an upcoming engine build, and I noticed a couple of the valves had some minor damage on the top of the stems. Some scoring and chips mostly. It is probably superficial, but I do not want to take the chance that the scoring would damage the rocker arms over time, and possibly lead to other problem down the road.

I happen to have a 350 parts engine as well, with #8 heads on it.

I am wondering if the intake and exhaust valves on the #8 heads are the same size as on the #7A Heads.

This is not a high dollar build I am going for, so saving a few bucks and not having to buy new valves is appealing to me. But I also do not want to tear down the 350, just to find out the valves do not match.

Thanks in advance for any help on this!

BillK

Decent stock replacement valves are less than $10 each. If you only need a few its probably going to be easier to just order some. Or depending on how they actually look any automotive machine shop should be able to lightly grind the tips on the ones you have.

brownbomber77

If you're getting a valve job anyway, may as well throw bigger valves in it. Very cheap power. You can also get Speedmaster stainless valves as another inexpensive option.

Tom Canfield

Thank you for the responses, however the heads are not going to have a full valve job, and having one performed is way out of budget. I plan to clean the carbon off the current valves, and lap them to clean up the valve seats, and that is it.

As far as replacing valves with stock OEM parts, that is not out of the question, but I have had contrasting answers on the size of valves that the 350 7a heads have. Some tell me that all 350 heads had the same valve size (except for the W-31 engines) and others tell me that the each head designation (#6, 7, 7a, 8, etc) had different sized valves. And I am have a hard time finding a definitive source on this.

But as I mentioned, if I can use the valves from the #8 heads, that will be my cheapest and easiest option.

Below is a picture of the valve damage, which is on at least 8 of the valves. No clue what caused this, as the heads came off of a parts car.

BillK

The one that is beat up a little will probably clean right up on the valve refacer. Do you have a machine shop local ? I probably wouldn't even charge you to do a couple if you brought them here

My parts books only show the different valve sizes by year. Not by head number.

Tom Canfield

Thanks for the response Bill, I will give my local shop a call after the holidays and ask. Worst they can say is 'no' right?

BillK

I cant imagine them saying no. Just ask them if they can "butt" a couple of valves.

edzolz

This looks like the heads have rotators. Looks to me like the rotators are not working. All of the damage is in one spot on the tip.

Altered 1978 350 Olds

I have 1972 7A heads and 1976 8 heads, both had the same valves when I did put them side by side.

Check your parts engine pistons when you disasämble it. That engine should have the smaller CC pistons compared to the 7A head engine.
Might consider to do put the 7A heads on the parts engine, use that as your rebuild core, or use the pistons from the parts engine in your build (if the bore is the same, not bored over at one time), to bump up the compression.