cus

Just got some bad news from the engine reconditioner.
Sent my heads off my 1973 350, No. 8 heads, to get new guides etc.,
he needed to replace the valve seats, & has machined into the water jacket,
one head is now stuffed. Has anyone had this happen to them.
He was saying that he thought someone had put in larger exhaust valves,
but I think the No.8 heads had the bigger valves standard,

regards, Cus

olds 307 and 403

They had the 1.625" exhaust valve stock, did they really need new seats?

coppercutlass

Now you have the perfect chance to bump performance a little and get some #4-7's for a little bump in compression. That is if you are keeping you stock pistons. After market pistons have huge compression killing dishes unless you buy the forged ones which will range from 6cc's to flat for the small blocks.

cus

Yes, there was one seat that was badly corroded, had been sitting with valve stuck
open. Are they hard to replace ?, apparently there is very little margin for machining.