I've seen some really nasty wrecks on the race track caused by people doing a less-than-perfect job of altering a steering wheel shaft. If you choose to make a change, enlist the help of a very skilled machinist, and the best welder you can find. I'd suggest machining a sleeve to fit over your splice, and after the shaft is welded together, cross-drill the shaft and sleeve, and pin it together so something other than the weld carries some of the turning load.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
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