Technical Rear shock mounts

A little help, I have a Model A frame that is stepped up 2.5". I am using a Model A rear spring with 4/5 leafs and a reversed eye main leaf . It will be mounted to a quick change using 40 bells. I have a pair of original bolt on shock mounts. I also have a pair of aftermarket, longer shock mounts. Seem like I read somewhere that the longer ones are better for a lowered application. I know that the shorter stock ones are different lengths and should be matched in length. What do you think?

Thanks Ken