1972 K5 Wheelbase after rear lift springs ??

[6600DURAMAX]

So installed a set of 52'' rear 6'' lift springs - it has seemed to shift the axle backward......... current wheelbase is now 105''. I have the ability to shift it with the new spring perches I have but am curious if I should ?

Dont believe the wheelbase will shift when the body weight is added?

It also seems teh spring perches are sill rotated down - even though I rolled the rear to about 23 degrees - did this because driveshaft angle will be about 26 degrees when installed

Need to weld everything down but want to be right first.