stock vs after market coil springs

[dondb]

Truck is a 69 c10 LB step side, original 307 three on the tree.

I just purchased a front drum to disk brake conversion kit with 2 1/2 inch lowering spindles. I also bought 4 new KYB gas adjust shocks.

Question I have is - while i have the U/L a arms apart do i keep same original coil (seems to be fine) buy a new moog coil or after market coil. I don't want to lower it any more then the the spindle will accomplish and plan to lower rear with a 4 inch lowering coil. I realize my original coil may have sagged a little and little rack is fine. Bottom line is are there any pros or cons to mixing and matching coils with original coil or new MOOG in front and after markets in rear. Not a big fan of spending money for new parts just because their shiny they need a benefit.