Does the pro design cool head come cut for I rings? Also what's a close to stock 500 cc dome size to go with or what should I consider for dome size. I've had port work done running v2 reeds 41.5mm mikuni and a Q pipe.

Also the coolant passages need to be restricted similar to the o ringed head you received from mhr. They don't weld up the cool head they use epoxy, which over time has been said to not be a permanent solution. Otherwise the use of a normal head gasket is required.

My stock head has been modified like the one sent to you.

So who's running a cool head with a head gasket and who's running one with o rings? What type/brand of head gasket are you running if you're running one with your cool head? Thanks!

Did you modify the coolant ports motoman?

I have a non o ring power head that uses the oem head gasket. The head as no step in it like the stock head, so I know it's got more compression. Unfortunately unlike other cut heads this one doesn't have the cc's etched into the head stay.

Maybe it's just the 87 head that doesn't come o-ringed then. That's what I have.

LRD and Duncan sold a few of the O-ringed heads. They stopped selling them O-ringed due to cylinder decks not being flat and customers Complaining that they would not seal properly. Pro design has always built the heads for other companies. Tom has never sold them as a O-ring unit only head gasket set up direct from pro design. I just ordered heads from him a month or so ago and this came up.

Tom may have machined all the grooves while cutting the domes and shell, it makes sense he would have the O-ring kits too.  He will custom cut If you order enough pieces. I just had special blanks done for my 250 stuff. Once I get the specs all figured out I will have him  cut everything all at once instead of having to charge double to set up on my machine for the final dimensions.