You could try to re-torque the head, but make sure you use the right torque setting... (Sorry, don't know what it is) If you over torque the head, you could warp it and create more of a leak amongst other things. You could also strip a bolt, or crack the head if you just try to tighten it more without having a specific torque to aim for.
If you break the seal, the only way you can use that motor again is by sending it to 600 racing to be re sealed. That is only happening if they rebuild it, unless you send it to them to repair and open it. If you break the seal, they have no idea what you've done inside it without a full inspection. So at that point, you might just as well send it to them to rebuild, and be done with it.
You can't turn a sealed into an unsealed. Not permitted by Inex.
Could you race it like it is? What side is it leaking on, and how much? If it just seeps oil a little bit (just enough to make the motor a little dirty, but not creating a slick on the track) and it's on the intake side, you'll probably get away with it. Keep an eye on the oil level every time you run it. If it's on the exhaust you could end up with an oil fire under the hood.... Not good.
If it's more than seeping a little, time for a rebuild, so you might just as well try tightening the head bolts a little. Overtorque by a smidgeon if needed. If that's not curing it, you need to rebuild for sure.
Just my opinion, but I'm someone else will have some other ideas!
Good luck,
Mike
