It depends...
If you cant the shocks inward at the top, the angle works to make the shocks feel softer, and makes long shocks "shorter"
On my 89 +-6" lift, I raised the shock mounts to above the axle tube CL and built a crossmember for the top mounts (used a piece of 2x2 hitch steel notched to fit up tween the framerails & mounted to a bumpstop bolt on each side... with holes starting 2" either side of center, every 2" for a total of 4? on each side of center.)
I had some hand me down gas-charged "white" shocks for +3-4" that are stiff as a board. I had to use the innermost two holes and they were like at 45*

but being so stiff initially, the cant helped them out alot. Any less lift would have made them too long though... they'd have bottomed out before the susp quit stuffing. At full stuff I had appprx 1" of chrome left showing on the shock rod and at full droop they had a couple inches left to stretch out.
Do yourself a favor and put
both shock mounts on the back side of the axle tubes and high enough to not be rock meat. I started out with one in front like OEM... 1st trip out, tore the pivot stud off. :viking: and that gas-charged dealie was like an air jack. Made fun sounds till I figured out Houston had a problem.