Thanks "thesals"! I shall give it a go, but might wait a few weeks as I've got a couple of car shows coming up. Will it harm the engine if I drive it as it is at the moment

NTFDAY...when I put it in gear it's like it's too much effort for the engine to keep going, it turns over a few times, gets slower and stalls. Like the extra load is too much for it, but it'll keep running if I accelerate at the same time, then once the car is rolling it's fine, even if it's rolling along without me touching the accelerator, until I'm at a standstill and it will die again if I don't help it.
It doesn't do it anymore now I've advanced the timing, but don't know how healthy it is for the engine to run 2 degrees over what it should be? As it's only a 260 I'm obviously not driving it like a maniac 'coz it doesn't go fast anyway, lol

Cheers