narrowing a 9 inch assistance

I searched but still had questions on tube and axle lengths.

bought a 9inch from a 72-74 torino. I know I'll have to cut off brackets and weld on spring perches as well as narrowing it. My question comes to the narrowing part of it.

66 rear stock is 57.25" axle flange to flange (or 52.25 with just the housing). This one is closer to 62.25ish" axle to axle flange. Also one side (axle tube) is about half an inch longer. I didnt check the stock 7.25 axle I took out before selling it to see if the pumpkin was center soooo.....

Here are the questions-
1. When narrowing the axle tubes do I make it so the pumpkin is centered or is it suppose to be offset in the car???

2. From what I have read the axles are also different lengths (half inch difference) and I found people are swapping a longer one for a shorter one but it doesnt mention the actually axle lengths. What is the axle lengths in a 9 or 8" axle for a 66 mustang and are they different lengths.

3. (going off question 1) If it is suppose to be offset then I just cut off an equal amount off each side correct? example rear is 62.25 so I would have to cut 2.5 inches off each side

Sorry for the silly questions but reading article after article on narrowing a 9" left me with these Q's.

thanks

and what about the axles??

I found a orig 66 rearend that has one axle as 30" and the other at 26" (approx) so that would be a 4" difference. would I just look for the same or just look for a 8" with the correct axles lengths

thanks bart. could you also measure the axle tube from the axle flange to the weld on the pumpkin please.
Jon