If I needed to crank my engine THAT long I think I'd best take the extra $700 I would spend on one of these batteries and spend it on the problem

I compared several of these batteries to the sealed lead acid batteries on the Interstate website:

For the same A-H
assuming the sealed lead acid batteries crank well (they always have)
these batteries are the same size.

Their advantage is they are half the weight of the sealed lead acid batteries Interstate offers.