23 to 18 spline posible?

OK so Basiclly i need the cluster gears and the whole gears with the imput shaft and bearing retainer in order to convert it to a stronger 18 spline unit, I was reading, and the mainshaft and output shaft are the same as well as the cluster gear shaft, the only output shaft that changes are the old short shaft A-body 833 trany that uses the small spline count output shaft like a 904 auto trany but the rest uses the same 30 spline 727 style one and newer short tailshaft A-body 833 also uses the 30 spline 727 style!

I will live this like that and use the 23 spline trany, if it fails then i figure something else, cuz if i need to spend 2000 in an upgrade i better save 2000 more and get a clutch assisted G-Force GR-5 or something in that range!