Swap 904 to 727?

Already went to 10" on front. Been looking for 8 1/4 or 8 3/4 rear end they are expensive even if you can if an a-body one.
I guess if that 7 1/4 goes I will deal with it then.
On the motor brackets I picked up a front end out of a 69 340 a-body, thinking I could use the k-member. Wrong, only to find out the 69 k-member is 1 3/4" wider that the 66. So back to school i go.