I am in the process of swapping to an ls from a TPI. When swapping the transmission crossmember, two bolts broke off. I have tried everything to get them out. Several cans of pb blaster, torches, several broken drill bits and they aren't budging. So needless to say, I have several questions....

1) any other options to get the bolts out???
2) is it possible to drill new bolt holes in the frame as opposed to drilling through/retapping the existing holes? I planned on using the Spohn 4L60e crossmember they made for this swap.

Any thoughts/opinions would be fantastic....

Depending on access you could try welding a nut to what's left of the bolt. Weld inside the nut so it forms a new head.

Unfortunately the bolts seared off flush. Nothing there to weld the nut too.

When I purchased new runner bolts from hawks, the heads stripped and I had to drill every single bolt to stick an ez out in there. You might try ez out if you can get a hole into the bolt deep enough. .....good luck. .

That's ok. If you can position a suitable sized nut where the head of the bolt would be you may be able to weld inside the nut so the end of the sheared bolt is fused to the nut. If the weld is good you may be able to back out the bolt using a wrench on the nut. Or drill etc. etc.

Pop the front seats out; take a hole saw or unibit to the floor pan right above them; do away with the stoooopid chinesium garbage captivated in the little sheet metal thing. Make the holes a size that you can get some plastic pop-in plugs in.

Very quick and eeeeeeezy; prolly will take less time from start to finish, than it took you to post the question.

A couple of whacks with punch & hammer should knock the nuts out of the frame member. They are barely spot-welded in place.

Sofa's method is one approach to replace those nuts.

Since the frame member is so thin there, I took a piece of 1/4" strap steel long enough to cover both mount holes, match-drilled it to the swap crossmember (mine happens to be Hawks), welded real nuts to the strap, opened up the hole in the frame members in front of the crossmember mount, fished the plates in place, and bolted in the crossmember. Spreads the load out better than just nuts or nuts & washers.