I have a manual 240 and a81 SD and think that the SD is very well suited for an automatic if shift points are set up right and the turbo and alls it plumbing is working properly I don't think you would gain much performance with a manual.

I have done some engine conversions and though they look good on paper there is almost always some hellish unforscene problems unless the conversion is an often done one with parts and imformation at ready............
William Rogers.........