Lady72nRob71

I need to know? 1972 stock 350, 7A heads.

Looks pretty straight forward in comparison with my old ford.
Of course, keep every part in its original place / order, block oil drains.

Remove retainer bolts and retainer, remove rocker arms, clean well, air up cylinder to hold valves closed, compress spring, remove keepers, remove spring, pop off seal, then repeat the reverse to install.

Is there anything unique to keep in mind? First time I have been this deep in an Olds engine.

2blu442

I've only changed seals with a rebuild on the heads. But what you described sounds right to me. I've also heard of using a nylon rope and feeding that down the spark plug hole, then by hand rotating the crank until that piston gets tight against the rope holding the valves in place. John

Oldsmaniac

Compressed air in the cylinder works well. There are better than the stock umbrella seals available on Ebay. They require no machining and look like the teflon ones but I think they are neoprene.

Lady72nRob71

I used the air fitting when i did my Ford last year - worked great.

Can you elaborate on these "umbrella" seals?
I have heard of the term umbrella before but do not know what it means.
I had already ordered felpro #SS70393 seals which are supposed to be umbrella type. Hope they will work... Recon??

This is the deepest i ever got into an Olds engine and it was not a warm welcoming...

rocketraider

I'd almost go ahead and order a set of valve keepers too. My experience has been that a lot of times they're knife-edged and when you put them back, they will cause weird valve-related problems.

Also be prepared to whack those valves pretty hard to get the retainer and keepers apart.

Lady72nRob71

Keepers, like these, right?


What is meant by knife edged?

Looking forward to "whack-a-valve"... Hope I dont break anything else.

Oldsmaniac

Here is the link to the better seals http://cgi.ebay.com/ebaymotors/POSIT...ht_2609wt_1167

These are not umbrella type. The stock ones are because they act like an umbrella to shield the guide from excessive oil but are not a great seal. They work but there are better types.

rocketraider

Those are the ones. They'll develop a sharp knife edge at the bottom of the taper, which allows them to go too deep into the retainer. That in turn allows the valve stem to go too deep into the retainer. When that happens, the rocker arm can't operate the valve properly- it won't open as it should and will cause all kinds of weird misses and backfires.

After learning the hard way with a couple of engines, I figure on a set of valve keepers anytime I do valve seals.