200tdi or 300tdi into a series?

[Jimmy]

I always thought a 200 was the best conversion but I keep reading about them getting old and parts slowing up, plus people doing 300s more and more. So what is best? My question relates more to an 6cyl series 3 (ex-mil GS).

And I assume the r380 is workable in both options, mated to the series transfer via Ashcroft.

Cheers

[JDNSW]

The advantage of the 200 is that it is the same dimensions as the Rover four, with the same bell housing and same engine mount positions. But since you are replacing a six, and apparently not planning to use the Rover gearbox, these advantages do not apply, and you will be better, for the reasons you mention, to use the 300Tdi.

John