Rear swing arm mounting plate, Rusted and broke 1/2 the bolts Options

[tracks914]

The 3 hole mounting plate on my project car (passenger side) is rusted pretty bad so I figured they have to come off for my resto so off they come. They seemed pretty rusted and tight so I soaked them from the top for about 2 weeks with penetrating oil.
Last night I went to take them off but I knew I was in trouble when they were spongy. WTF, grabbed the impact and got 3 bolts out OK and 3 broke off! (IMG:style_emoticons/default/headbang.gif)
Now this is going to be hard to get the broken bolts out. I might have to resort to drilling and re-tapping the holes unless some has a better idea?????Anyone ever have these seized in before??(a stupid question but....)
BTW I now need a passenger side mounting braket (plate) and shim!!
Tx

[mihai914]

Had it happen to one bolt on the previous car. It's too late but did you heat them up before? Anyway the fix I did was to drill out the broken bolt, it's pretty hard to drill, you'll need plenty of bits and try and stay straight... After drilling crooked once then straight the second time, I just passed a long bolt that went all the way through with a washer and a nut and it held really good.

Another option may be to replace that outer console ear, the end result may be much better that drilling... It may be even more time effective.

As for tapping a new thread, it may be possible but those threaded "tubes" are pretty thin so you won't have plenty of chances.

Good luck!

Edit: Added some pictures for you.