Spitfire 1500 O/D on a 4 speed tr7 box

[TRubble]

Hi Guys,
still looking for options on the 4 Speed gearbox. Before you all cry 5 speed conversion
I would like to keep the 4 speed in some form if at all possible.

It has been suggested by some guys in the know that I could use a spitfire 1500 O/D unit and the necessary shafts to attach to my 4 Speed TR7 box thus keeping those
wonderful ratios and also giving me a little less frenzy higher up. Not to mention the fuel economy.

Does anybody have any experience of such a conversion? I realise a little fidling with mounts and prop shaft will be necessary but anybody with practical experience would be a great help in my pondering.   :-/

[thescrapman]

What you are proposing to make is already out there, a late dolomite 1850 box.

Still don't know if it will fit mind.

If it did I suspect lots of people would have done it.

Cheers

Colin

[andy thompson]

Why wouldn't it fit? Same block and clutch - maybe the propshaft and mounting is the only area in need of customizing - probably not been done as most would just go for the 5 speed.

[Nick Jones]

Must be some good reason - very obvious conversion else and never seen / heard of it being done.  Maybe tunnel clearance issues - OD is pretty fat and far back?

In answer to original question, you could use the J type OD from a 1500 Spit or dolly but you also need the various adaptor castings and the gearbox mainshaft from and OD box.  As has already been pointed out, this is all a bit of a waste of effort unless you happen to have all the relevent bits kicking about as the Dolly 1850 box with OD is what you want already.....  5 speed is alot less fragile and parts to fit it already exist!

Nick