I hope you're planning on getting your wallet out alot, lol

If this is a race only deal, than I would be looking at:
a 300M or Hy Tuff input and output shaft.
An aluminium high/reverse drum with the big piston.
A Griner Transbrake
A roller rear support
Alto Red Eagle frictions and Kolene steels
Red lined solid bands

I am not sure if the factory steel plantaries will hold up at that weight, so a call to Pro Trans for straight cut gears maybe in order.

This would also be a high maintenance trans

If you are going to street drive it, build a 727

I am assuming Ian it was the trans I saw on the ground on the Heathcote website? Or did the diff go and take the trans out with it?
AL.....