ULT/ Retro Valve Mod?

[trxtr]

I've heard mention of the Retro Valves being drilled out to accept the ULT. Anyone actually done this yet? If so, how exactly? what size drill bit, depth, finishing, etc. I'm willing to butcher a valve as long as i have a reasonably acceptable chance of not turning it into a paper weight.

thanx
trxtr

[Remington]

Just send it to BradAGD. He'll mill it out to AGD's specifications and that way you'll know it's been done well.