When I had me Series with a V8 running carbs I looked into getting it converted to LPG. I'm in Hants, but spoke to a guy down Horsham way (sorry, dun't have his leaflet anymore) & he said it was barely worth the conversion if you're running carbs.
He said he'd done a few carb conversions and the savings were negligible. You really need to be running an injection system to make it worthwhile.
Me current disco has a quite basic system (third generation system I think, though might not even be that!) & means I can afford to run a 3.9 whilst covering a fairly high mileage.
In the really hot weather it's not been happy to change to LPG once it's upto temp', so on a run if I stop it needs to cool for a fair while before it'll switch over again.
The most recent systems are almost infallible if set up right, but for a Classic on carbs it won't be an option to you.
If you do it, I'd be cautious installing too small a petrol tank. I know where all the LPG stations are across the counties I regularly cover. That said I've often got to an LPG outlet only to find they're out or the feckin pumps bust! If you're going to install a small tank, get yourself a jerry can as back up!
Don't get me wrong, it's great being able to afford to run a V8 rumbler as an every day motor & I love it to bits, but it does take a bit of thought and planning to not have to fall back to running on guzzleine too often.
Sorry, LPG is great, but it's no panacea, spesh' on carbs!
