Mark, loosen the bolts down one side (not forgetting the front one!) then support the weight of one side of the body on stands, then do that side one block at a time. You should be able to lift it so the blocks will slide out without lifting the body excessively.
Metallurgy isn't my field. Open question - what grade of bolt would you use here? A quality HT presumably?
Also, get bolts with unthreaded length suitable for the length of the spacer so they're a nice snug fit in the spacer.
Thinking out loud, would a better spacer design not be steel threaded from each end and a bolt threaded into the spacer from each end - perhaps even two bolts at each end? That would be a far more rigid setup than the typical 'both through' types you see, though not as easy to fit.
Metallurgy isn't my field. Open question - what grade of bolt would you use here? A quality HT presumably?
Also, get bolts with unthreaded length suitable for the length of the spacer so they're a nice snug fit in the spacer.
Thinking out loud, would a better spacer design not be steel threaded from each end and a bolt threaded into the spacer from each end - perhaps even two bolts at each end? That would be a far more rigid setup than the typical 'both through' types you see, though not as easy to fit.
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