sounds silly reply but i hope it makes sense when i drove it home 140 miles it was fine pulled lovely no smoke ect, but the throttle cable was cable tied to the rocker cover and i didnt put it back like that when i changed the lifters , i thought it should run under the plate on the rocker cover so was going to change it back, since i ran it with out it cable tied its sounds like the idle speed is to low and light is flickering on a very slow tick over near to the point of cutting out and will cut out if coming up to traffic lights, but i wanted to get the annoying tapping noise sorted first and take it to be set up