The left side bolts are 5/8"-18 coarse thread and 1.75" long. This side was pretty straightforward to replace. The idler is sorta right in the middle of these bolts but you can snake a long extension right next to the idler and get onto the bolts. I found out the idler can be removed easily and makes the repair process much easier. Figure it out on the right side.
I was also missing the engine/drivetrain bolts in the center. The left side is 7/8"-11 x 2.25". One of mine was missing but I replaced both.
On the right side was the fun side.
One cross member bolt was busted off and the other was still in. I used a Taller jack (made from a Kit from Brennan's Garage) to ligt up the track and remove the center idler. 4 x 1/2" bolts.
This gave much more access to the bolts. I found a 10" 1/4" Dewalt drill bit at Lowes and used it for most of the extractions. I took the busted bols and cut the shank down to about 2-3", then drilled a 1/4" hole down the center of each. I used these as drill bushings to center drill bit and keep the drill bit more or less in the center of the busted bolts. It worked pretty well and once started the drill bit worked just find. I tried to use a left handed tap and bolt to thread the busted section out but that didn't work so well. I moved onto the 9/32 sized extractor and that actually worked really well. I did soak down the broken bolts with PB blaster the day before. I used an 8 sided socket on the square end of the extractor to reach into the hole. The 5/8" broken bolt came out with the 1/4" without much fuss.
The engine side bolts are 7/8"-11 x 6" and one was busted off. There is a spacer bracket on the inside of the frame that these slide through and bolt into the engine. I used the jack to push the track down so I could get better access to the busted 7/8" bolt. I drilled a hole in it with the same type of bushing, I did step up to a 10" x 5/16" drill bit from McMaster. The extractor worked very well again.
Replaced the 5/8" bolts with 12 points, the 7/8" are Grade 8. I used orange locktight with NordLocks on all the replacement washer.
updated pics:
Also on the right side the 5/8" bolts are not full through on the back side, they are up against a spacer. The Left side ones are open behind the nuts.
Few of the bolts had been replaced with Grade 5's so they were removed and now are Grade 8 or higher. I messed around a bunch with left hand taps and bolts trying to screw out the broken pieces. In the end the extractor worked the best, with a square of 8 point socket on the end of it. The 1/4" bit works good for stating and may be be enough for a good grab with the extractor but the 5/16" hole gives it a even better bite.
Hopefully helps someone else.