69 Camaro Subframe Connector Question

[Scubachef]

Tried the search function but no answers found. I’m installing DSE subframe connectors and the template gives a measurement of 4.75” to the pinch weld on the rocker at the rear. Mine is 5.0625”. I know that there were wide tolerances for these old cars but I’m trying to be as perfect as possible. Is 9/16” too far out signaling there is something I need to look at before I start cutting? The front measurement spec’d on the template is dead on at 5”. I squared the subframe, it’s an 1/8th out when measured diagonally, which I thought was probably as good as I could expect. Has anyone run across anything that I need to account for or is this just a case of an old car with loose assembly specs? Thanks!