ZF!!
Hi
I chose a new ZF (RBT) 5spd for my car CAV106 for following reasons;
1) CAV can be factory fitted either Getrag or ZF. g50 was not available option.
2) ZF uses off-shelf bellhousing, clutch assembly, flywheel and starter. With g50 you enter a whole situaution of make to fit parts.
3) ZF provides the lowest possible mounting of engine for centre of gravity and 351 engine clearance, without going dry sump.
4) Your choice of ratio, plenty available. Do your calculations well once you have the dyno sheet for your engine.
5)Originality, simplicity and resale value of car.
With all the mods required you are not goig to be far off ZF price. G50s are becoming scarce and I know of 2 new units for sale in South Africa and they wont be cheap.
As for ZF, go new, cos if a 2nd hand one needs repairs you may as well have bought a new 6spd.
Good luck
J Hamm