I took an allen wrench, cut it off so it would fit in, and with a small box end wrench, put the allen head into the boxed end of the wrench, and with a lot of patience, was able to tighten the bolts.
I have lengths of 1/4", 3/8", and 1/2" heavy wall Stainless tubing I use instead of a wrench, give that extra leverage,
I've been searching for where my transmission was leaking from for a week and found this thread, Both exhaust hanger bolts were loose. At least I could get a normal allen into them behind the V&H headers.