[TR] TR6 and TR4A IRS Frames the same?

[levilevi at comcast.net (Bud Rolofson)]

Listerati,

Apparently the steering rack mounts are different between a TR6 and a  
TR4A IRS frame.  Are the motor mount locations different or the same?

I read (on RATCO's website) where the two frames are identical except  
for the before mentioned steering rack mounts.  Is that the only  
difference?

Are there any more differences?  Most importantly the motor mounts.   
What issues might I face if I tried to put a TR6 engine on a TR4A frame?

Thanks
Bud Rolofson

71TR6 CC57365 (Good 6)
66TR4A CTC57806 (The Wreck-Almost parts)
66TR4A CTC57529 (The Project)
71F-250 Camper Special (Triumph Support Vehicle)
Z-50A Hardly Davidson 1977 Honda Mini-Trail Bike (Triumph Pit Bike)
levilevi at comcast.net