The compression calc tells you that. Its always on the low side. I few guys over on B bodies have done this with great results. Don't have any numbers to prove, but Malex over there says he could feel a 2 pt increase in the seat of the pants using these heads and I still believe this head for whatever reason needs high compression 12.5:1 or higher to run strong. Malex with a 505/12.8:1 compression in a B body at 3450# and these same heads goes in the 9's. The heads get bolted on today after I check the piston/valve clearance.

I believe that there was a head with this done to it. . With a 60* below the 45* and a seat width of .059 to bring the 30* back up to the chamber would make it noticeably wide, like a quarter inch, which would be noticeable even with valve in.

I have Serdi cutters used in a Bridgeport. I have made errors where I have made the seat to great of a diameter, much less than .050 and it takes a considerable cut to reduce the Dia.

I believe and follow your knowledge but for that head to have been brought back to 2.200 I would think would stick out like a sore thumb.

I'm out on this as well.

Can you post a picture of that setup? When I started looking for a mill my first requirement was that it be big enough to bolt a head to. I haven't invested in the hardware to cut seats.

The one intake seat I cut would have had a .040 wide 45, with an OD of about 2.240.

Without a doubt one seat was cut that way.

What was done to facilitate the use of a 2.20 valve on that seat I have no idea.
But after doing this as my job for 30 years, I can tell you it would not require excessive valve sinking to make that work.

A few minutes with a couple of seat wheels and it would be good to go.



I have no doubt that had we seen pictures of all 8 intake seats with the heads all apart after cleaning and media blasting, it would have been no trouble pointing out which seat had at one point been cut for the 2.25 valve.

There are options to get around the sunk valve if it were too objectionable....... one of which is to just replace the seat ring and start over.

You'll need a 42" or 48" inch table...the 48 can tip when pushed to its outer limits though if not secured well to the floor.
2nd pic is some of the tooling

No big deal right now Dwayne. I don't doubt you did the work. I eye balled them before they went back on and didn't see any sunken intake valves. Everything looked uniform as assembled. We will figure this out next time they come off. All bolted up and torqued to spec now. Think I will clean up the ports in the intake and give it a coat of semi gloss black before it goes back on. Thanks for everything guys.

One other thing I failed to mention was that the valley tray rail on the inside of the heads did not require machining after having .045" removed from deck side of heads. I have about .015'-.020" each side of tray. Billet tray fits just fine. What would be best way to seal this edge?

nice bead of ultra black. ultra grey, or the right stuff.

After I had my Indy heads milled I went to local parts store and pick up a roll of gasket paper and a bead of silicone work great.


Then my buddy used a Indy valley tray with his Victor heads and filled in the gaps with just silicone after 3years now it's time to redo his

ok, I used the right stuff on the last tray. Had to saw the right stuff with one of the women's steak knifes to get the tray off. Think i'll use black rtv this time. Thanks guys

I use a Exacto hobby razor knife to cut the silicone