Is there a way to get the 2.70 1st gear

It probably wouldn't cost much more to swap in a low gear 904 than to buy a low gear set for the 727 and I believe the 727 low gear sets are straight cut so their noisy/drag race items. Yet even then you'd have the traction problem. You need to get with a guy that's good with suspension to get that thing hooking. Lots of us have no problems running low to mid 12's with nothing more than you got. I have a 408 in mine with nothing more than a cheap set of Nitto drag radials and it hooks pretty decent. Enough to run 12.20's