So I am running a built 403 in my '65.. and the previous owner slapped chrome valve covers on it.. I want to go back to stock steel covers. Am I limited to just 403 covers? Or are they interchangable with other years?

 

77 and later SBOs use less bolts, 5 or 6, I can't remember, while the 76 and earlier heads used 10. Yes, they are all interchangeable. There is a chance that whoever built the 403 used older heads with the 10 bolts on them anyway.

 

He has the 4A heads, 5 bolt covers.
Chris, you're going to need to get a 5 bolt cover, unless you want to have some extra unused holes with the early stuff- will easily be a driveway leak, and just not look right.
Now if you went to an early set of cylinder heads, you could dig up some cool, original 65 covers to put on it. One will not have a PCV, nor crankcase vent on it at all-plain & bare (10 bolt covers).
Jim

 

I have a set of factory 403 valve covers if you are interested. They need cleaned up and painted but will work for your application.

 

yes.. I am intersted. PM me a price. Would need them shipped to zip code 85083