Join Date: Mar 2002
Location: Austin, TX, USA
The trick is going to be keeping metal shavings out of the unit. If you can't refurbish the threads without getting metal in it, your SOL.
Look for some rethreading taps. They don't cut quite like a threading tap - more like push the threads back into shape. They are typically blunt on the end and might allow you to at least get the first three or four threads. I've seen them at sears, but it's been a while so I can't say much about them. Beyond that you're going to have to find a hydraulic's specialist or replace the unit.
68 Coupe, 350 w/ Edelbrock Performer RPM heads, cam, intake, 700R4, Dave's small body HEI