Need to shorten shafts for a narrow track Sierra based DeDion.
Any chance of an 'official' stance on best practice and wether SVA
will accept ? The Americans have enough techniqes for one to be
acceptable surely ? Main prob. would seem to be metallurgy; mild steel
Mig wire and hard high alloy shaft sounds a bit 'iffy' to me. A failiure would
seem likely at the change in material, diameter and heat treatment point
due to the many cycles of torque variation, a different problem to
prop shafts. So would think 'machine, shrink and braze' a better option but
it would leave a 'bump' obvious to the examiner.
Jim

Its very easy to over think good engineering practise on these things. If your not happy with cut/shut and sleeved then what about custom made one piece shafts. Just my opinion.

I have seen a failure of cut and shut shafts first hand. could have been nasty but thankfully no one hurt.

I have done it for mock up but will be getting one piece shafts made. I'm not willing to take the chance

My car with shortened driveshafts passed IVA last October without a problem The tester asked if the shafts were shortened and I said yes.

I think as with most things it depends on how well it is done, and also what power you're putting out. I'd say as long as they're properly done they'd be ok for stock power, maybe +20%, especially since the car they're going in is much lighter than the donor.
As you say metallurgy is the main problem. As long as they were annealed and re-heat treated don't see a prob.