Rear Oil Seal Conversions

[Mike Francis <mfrancis@triax.com>]

Does anyone on the list have any experience with converting a TR4 engine to
a rubber rear crank oil seal? I am currently building an engine, and it
looks like the way to go. I've never seen one of the alloy ones that
doesn't leak. 

I am unsure of the dimension that the crankshaft needs to be machined to
though, and I am therefore reluctant to have it done. Someone told me
63.5mm, but I don't know if this is correct.

Any advice would be helpful!

Mike Francis
'63 TR4