Rich,
I'll post some pics with dimensions this weekend. I need to finish the 'new' motor mounts for the pics to make any sense.

All,
I'd planed on using 1/2 of a heat shield on the top per suggestions on this thread, but I don't believe this would solve the problem of the tail pipe length (unless I'm missing something?).
The JC manual calls for a 20mm gap between the exhaust nozzle and the front lip of the pipe - Not including the bell mount; That's what I'm trying to achieve.
I should know this weekend how far the JC120 will need to go forward to allow the use of this pipe. I don't think it will be possible tomove it far enough.(wouldn't it be ironic to have toactually adjust for a nose heavy CG...Batteries in the tail cone...LOL) As Rich P mentions the forward bulkhead supporting the motor mount beams becomes a limiting factorto the engine mount moving forward.

Aside, kudos to SM for not pre gluing the motor mount beams at the factory. This allow much flexibility for the builder to custom fit the motor mounts for their particular installation.

Thanks for everyone's help, I'll keep you posted on my installation.
Regards, Jim