BTW. I've sweated, shrunk fit, interference fit lots of parts over the years, mainly to rework seal or bearing areas on shafts.  The  point?  It's typical for the sweated-on sleeve or ring or whatever to creep off the shoulder (if there is one) a thousandth or some thousandths as it cools.  My ring gear crept off a  thousandth in one area about two inches long.  I pegged it in place with a 1/4" flat-nosed punch after it cooled (one hit).  

Al's Ring Gears

Re Joblot Automotive. It's my understanding they have closed up in the last year or so..Unfortunately, I don't have any info as to where their stock may have gone..  Anybody know?..


Paul

Just flipped my ring gear this summer.Works fine.

you can flip over the ring gear people have been doing that forever.

I had this problem a few years back, I think most of the major suppliers were getting their ring gears from the same source they were made in mexico and
  they were slightly undersized  no amount of heat would make them fit.  they may have been sized for a small block Ford.  I finally found an NOS one from
  Joblot in New York but I'm not sure if they are still in business. 

I don't think you are suppose to do that. The flywheel and ring gear surface aren't a perfect 90 degree edge, thats why the ring gear has a small beveled/chamfer on one inside edge. That side goes against the fly wheel. 
I bought a Pioneer from Rock Auto and a little heat from a torch, light tapping with a hammer and it went right on..

If the teeth on the ring gear are only worn on one side, you can just flip it over. Save you the trouble of getting another one.

  Ron Lane,  Meridian, ID

Y block flywheels are same except in hole locations for 11" clutches, but what i have found were some ring gears were too small in the internal diameter to expand far enough to fit, these i,m guessing were imports and wrong.


  AussieBill            YYYY    Forever Y Block     YYYY

 Down Under, Australia

I'll throw in my two cents on this one,  My general "rule of thumb" for  "press fit" is.001 per inch of diameter, so, .015 would be acceptable for a 15" ring gear.  Be careful with the torch; 500 degrees is all it takes to remove the hardness from the heat treated ring gear.  Maybe....cool the flywheel as you said and oven the ring 200-300 degrees....should drop on.