I had the heads on a Olds 425 redone, they shaved the block side and didn't know that if you do that to an olds engine you have to shave the intake side. Heads were done a few years ago and I don't know how much they were shaved. any suggestions on what to do to fix. spent $500.00 having the heads done. and Yes they leak on the intake side. Engine has very low vacumn and builds enough pressure to blow oil out the dipstick tube.

 

Sorry I can't answer the technical aspect of your question but there is a 65 Starfire at my local yard with the 425 and the heads are still on it. If you wind up having to replace the heads or would just like some spares, let me know pretty quick. Not sure how long it'll be there.
Randy
w70442@hotmail.com

 

I would not pull the heads, just yet.

Oil from the dipstick usually indicates positive pressure, indicative of blowby past the rings. Low vacuum can be from a variety of problems. Timing, for instance. Points wearing out, can cause timing to change, and cause low vacuum.

Most shops do not cut large amounts off of heads, only if they are warped badly, through numerous builds---or if you pay for them to do it. I highly doubt if they would have cut more than .020" off. Stock type gaskets will easily handle light cuts like this, without leaking, properly assembled. I don't feel that milling the intake faces will help, unless they are severely warped.

I would have the shop who did the heads give it a look-see, checking tune, compression test, leakdown test, discuss how they worked over the heads.
Also have someone independent from that shop inspect it.
There is obviously an issue, it never hurts to have several, well trained eyes look it over first.
And that will be far better than inspecting over the net.

My Opinion.
Jim