Got a doozle FL and a K series Rover.
Had the doozle FL just over two years and expectin' it to go another ten at least.
Had the Rover eight years now and had rough running problems when we got it.
Dealer did a few 'fixes' but it was never right. After four years eventualy deteriorated enough to diagnose porous head (actually leaking tho' alluminium). Changed head (S/Hand) and fitted new type gaskets etc. Two years later HGF- water in oil - the works.
Had head skimmed and and another new type MLS gasket etc.
That was two years ago now and other than a failed CAT, exhaust system and Oxygen sensor its now running ok. I like the Rover and it's K eries engine but I do my own spannering and could just not afford the servicing bills to keep it running if I didn't.
Would I try the K series on gas - NO the design just won't take it.
Some have done it and it worked - good luck to them, they rode their luck and won. Many have found the standard K series OK in their FL's , ask NI.
It's your choice what you do, check out the conversion cost and returns, then decide - do you feel lucky?
Do let us know what you decide.