Been hard pressed to find the correct 5-bolt hole gasket for the 70's Olds 350 in my kustom... have had to settle for more common multi-bolt hole gasket, eventually leaking. Anyone recognize the particular year/model of this? Was it just a unique 5-hole model they ran? Have googled w/o success. Tryin to recover stamp ID info of years past. Thanks for any help. Sent from my SM-N975U using The H.A.M.B. mobile app
They eliminated the extra bolt holes and glued them on with RTV from the factory, no gasket. They were bad about leaking even then.
You can see the xtra dimples/bosses for the other bolt holes that are not there, If the heads are drilled for the holes find valve covers to fit
Heads have same # of holes. Before this mill, I had a '72 Olds in it, had the several bolt holes in it. Sent from my SM-N975U using The H.A.M.B. mobile app
IMHO I would use a valve cover gasket as a pattern and drill the remaining holes into the valve cover. That should correct your leakage problems. As far as I know all the heads have all the holes drilled and tapped in them from the factory.
Went back to the shop to recover stamped ID info... a source online had 3A stampings for 1979 heads, 3rd pic is the engine ID stamp on the flange near cylinder #1 at front left, I believe it's from 1977. Tried a combo of years n models through Summit & Rock Auto, no match for the 5-hole pattern in the heads. Will have to try again for a good seal. Oldsman's suggestion is interesting, is it to just screw/fasten gasket to flange/blank 'ear', when it's not over any head metal? Sent from my SM-N975U using The H.A.M.B. mobile app
This is the only sealant that we have found that will keep things sealed up, and we work on Hot Rods and Muscle cars all day long. We use this to seal the new gasket to the surface and to the head.
I'm not really sure what you were looking for, but if you are looking for pictures of heads with 5 valve cover bolt holes, just go to google and search images for olds 307 head and you should find plenty...I did... If you were searching for gaskets with only 5 bolt holes, you probably won't find any. The "right stuff" suggestion above is probably where you'll end up. Sorry. Although I'd see about trying some Fel Pro cork 10 bolt gaskets, if you can get them. rockauto lists them, 5 bucks a pair, plus postage.
Like I said get a valve cover gasket for a 1973 year engine and use it as a pattern to drill the holes in the later valve cover. That will get you the holes in the correct places to match the threaded holes in the cylinder heads
Not only are there no bolt holes in the head, the bosses needed to drill and thread them are not there. Cat, your best bet is to just use Right Stuff. Make sure the cover gasket surface is as flat as you can get it, put a thin layer on both the cover and the head and let it tack up before installing. Don't over tighten it. If you use a 10 hole gasket, use cork and fill the extra bolt holes with RS. Thin layer of RS on each side. Some gaskets have metal rings around the bolt holes or inserts in the gasket to keep it from being squeezed out. Try to use those if you can find them.
Even the king of Oldsmobile's only shows the 10 hole gaskets.. https://mondelloperformance.com/product-category/gaskets-sealants/
did you see that picture I posted above? late model junk heads....they quit putting the holes in them, and the bosses for the holes.