Guys,
I have a slight problem and need some advice. I need to go to a 1.535" dual valve spring to get the right pressures for my solid street roller cam. I currently have 1.460" duals the head was cut for - but going to the 1.535" has me a bit worried about hitting the water passage. The machinist took the 1.460" spring cutter and just touched the original depth and everything appears ok. I am installing .050" longer valves and could put a .1" shim in the 1.460" hole and take the 1.535" cutter to that - will that be enough not to hit water? Somebody must have done this before - what are you guys doing to get the bigger springs in these heads? Many thanks....
Craig

I believe that is the way you have to do it with these heads. However, I have never done it before so I can't say whether it will work or not. If you are running that drastic of a cam though, sounds like a good time to upgrade to better heads.

Yep. Thats the best way I ever found, but I used to start with a .060 X 1.255 dia. shim on the bottom before I made the first cut. Put oil under the shim, then when the cutter hits it, it will spin and act as a stop, not allowing the cutter to go any deeper. Since most springs have sort of round corners on the bottom, we used to round off the bottom corners of the cutter to match so we didn't make square corners at the bottom of the hole we were cutting. No need to make um any thinner than necessary.

Cool!!

Figured as much.. pdq67