I don't think its a lack of knowledge about how good the B18/20's are that lead to the V8 conversions, its the V8 themselves, You love them or you don't. I have owned one or two over the years and its a combination of the torque and the sound and tunability of the Rover.(And have I mentioned the sound)
150bhp as standard but back in the eighties my SD1 with a Janspeed exhaust, piper cam, some headwork and a holley carb was pushing 180bhp for not a lot of money and was an absolute beast quite able to see the wrong side of 140 on the clock which for back then was awesome to me at least in my early twenties and that car was abused on a daily basis for a few years and never let me down.
For me the sound of a V8 in full song is better than any four pot will ever be but that's just my opinion
