As said above some work is needed to convert an Auto engine to fit on a manual gearbox, see links below.
It used to be not worth doing this conversion but as the supply of manual Mini blocks declines it has become more common and worthwhile for the effort involved.
How to Convert a BMC A-Series Cylinder Block From Automatic to Manual:-
To fit a 1275 auto block to a manual, apart from drilling the dipstick hole, there are a few mods needed to oil plumbing:
1. Auto block doesn't have the drilling all the way from the oil pump to the relief valve.
2. Auto block has 2 holes in the relief valve seat `cotton reel' to let oil get into the main gallery, because the normal filter flange is blocked off with a plate- the motor's lube oil comes UP the banjo pipe from the auto trans to the motor.
3. Auto block pump mounting recess is .250" deeper than in a normal 1275 block.
According to one of the Mini magazines a lot of auto Mini blocks are also being converted in Japan where many of the Rover Minis sold were automatics.
Edited by mab01uk, 31 July 2020 - 12:08 PM.