Hey all, I am building a 64 Falcon Gasser. SBF power, mostly street driven. Using the Speedway kit up front. My question is how to get the added height in the rear. My springs are pretty tired and stock replacements are reasonable. My question is can I just move the perches to the top of the axle and use stock replacements? Or go to a spring shop and get a heavier spring made with more arch? Help.