OK Chris, my responses in bold:
Step one is to verify there are no additional loads on the car. Is the handbrake dragging? binding calipers? That sort of thing. Thought about that one myself tonight. Was going to check tomorrow. Brakes have all been rebuilt in the last couple of years and should be good, but it's an easy check.
Then, how confident are you of your trip meter for the recorded mileage, both before and after - perhaps it was flattering to deceive before? GPS calibrated, and I checked the route out using Google Maps, which returns a distance to within a flea's penis of what my trip meter said. There are also reasons to believe that pre-Dakota Digital the distances I recorded for consumption purposes were accurate (including, again, the use of Google Maps in more recent years).
Then you're on to the engine. Start by checking for air getting into the induction system, vacuum hose to servo, pipe to vacuum advance retard, damaged seals around throttle spindle on the HIF's etc. Brand new rubber all around the top of the engine in 2010, checked for leaks during the last carburettor faff in March. Dead quiet engine at idle, by the way. No hissing, no rumbling, just a very smooth and quiet tickover. For the latter a very careful listen for hissing - use a piece of old heater hose as a stethoscope. In 2010 the carburettors were inspected by a bloke called Larry, who runs a little business called Swift Automotive specialising in SU, and all things BMC. He pronounced them in good nick, but doesn't have a workshop so wasn't able to tune the car for me, otherwise I'd have got him straight onto it rather than taking it to the subsequent monkey (a self-proclaimed classic car specialist...)
Then you're on to the ignition system (Pertronix). A change of plugs (brand new) and of distributor cap and rotor arm (not new, but not at all worn) are a good idea, the plug leads too if they are not recent and good quality (not recent, but good quality). Then verify that the vacuum advance retard is working by sucking on the tube and verifying that the distributor base plate rotates and returns fully. A twist of the rotor arm to verify the centrifugal advance and retard and to see it fully returns to the stop by the springs (both done just the other day). Then set the timing (checked the other day at 6 degrees BTDC). Verify the timing marks first by using a pointer down a plug hole - pencil or similar (I calibrated this when I had the front pulley off last year). Once set dynamically at no more than 1,000 rpm, see if a small adjustment either way speeds up the engine at all. If it does use that setting instead (not done, didn't know about that. Will give it a whirl, Pearl).
Then it's carburettor time. I think you have rebuild kits on order? Not I. Have you confused the unforgettable, inimitable me with some other geezer? Going by Larry's 2010 appraisal of the carbs I shouldn't think they were needed. If so we'll tackle this after you've fitted them. In the meantime make sure you have two colourtune plugs and a carbalancer if you wish - I simply use that piece of hose stethoscope to listen to the intake hiss. Been thinking of buying them - now must toss up whether to take the car to the Rover club gaffer or purchase the stuff myself.
Enjoy! ???
