Something most people do not know about the overdrive units on these Spitfires. Most people are only aware of the A type having a .82 or (22%) taller ratio but they also had the .78
J type = .8 (25%)
A type = .78 (28%)
So I am just curious as to why you did not go this route? The J type are much more abundant over here in North America as they were fitted to all of the Spit 1500 cars with overdrive. You can also find them on Volvo transmissions which came standard I believe. These .78 A types you probably would have to find over in Europe. So more work but possibly better efficiency as well. Food for thought if nothing else something to look into if you ever get the Centurion optimization bug again down the road.
GH
