MTFCA Forum

Wanted thunderbolt valve cover for overhead conversion

Wishing you good luck in your search, that is going to be a rare bird!
If you are going with the loss oil system, the Frontenac cover might work or like I did, original Cheverolet 1 piece rocker cover. Even out of the box, if using the Gern Thunderbolt cover and a pressure oiling system, the Chevrolet head needed to be machined around where the cover would seal and return oil system made to drain the wells.
If you have the Jern adapter plate, Olson Gaskets can make the head gasket if you need one. http://www.olsonsgaskets.com/
Also, here is a post that shows some of the work that can be done;
https://www.mtfca.com/discus/messages/29/25434.html
And even more;
https://www.bing.com/search?q=MTFCA+Jer ... cc=0&ghpl=

On my 28 Chev 4 cylinder sprint car I had a new Jern valve cover and it sorta fit the cylinder head machined surface. I used black gasket sealer and fashioned rubberized damn seal inside the oil galley up against the boss for the original valve cover to sit on.

I had no oil leaks and was able to oil rockers often and keep the engine clean.

frontyboy