Technical 32 chassis builders, question?

been working on my roadster ch***is, going to use a 40 ford rear with 36 rear bones, in need of the measurement from the centerline of axle to centerline of rear spring, i have measured and came up with 8 inches but i know when you mount the bones you will have to put the spring eye on the end of the bones back in position by heating and bending them, probably gonna change the dimension somewhat. so anybody have the measurement to where the rear x member should mount from the axle centerline? thanks hot rust

 

Seven and a half inches centre to centre when using 36 rear bones. works every time.

 

thanks lowsquire