Nominal* Spitfire propshaft lengths are:
up to 1974 (non-OD) 41.25"
up to 1974 (OD) 38"
1975 & later (non-OD) 38"
1975 & later (OD) 37"
*Nominal is a key point here. Lengths can vary (especially the
later sliding-spline-baked-bean-tin unit) up to an inch ISTR. I would
try to end up with yours being in the middle of it's telescopic range.
In any event 2.5 inches sounds like too much.
> I am in the process of swapping out a normal gearbox for an overdrive unit
> in my 77 Spitfire. I am planning on using the existing prop shaft, after
> having it cut down and balanced, etc. An article I read on the subject
> stated that you need to have 2 1/2 inches removed from the shaft. Does this
> sound correct to anyone on the list who has done this?
"Sometimes one pays most for the things one gets for nothing."