After many pissed off moment at hearing my supe clunk on take off and sometimes under braking and reversing, i think i have found the problem.
Read somewhere on here some time ago a thread which explains this problem about the clunking,this is caused by the engine mounts,anyway thinking it was coming from the drivers side i replaced the mount, and it never cured it,although i purchased one for the other side i did not fit it because engine transplant was on the cards so i left it with a view to installing it when the new motor went in, anyway cut a long story short i had the engine out and i wasnt till i started to wipe them both down i noticed that the one i never replaced moves in the shell and you can hear the clunking on the case if you turn it with your hands, im prety sure its the issue and i should hopefully be clunk free very soon, just wanted to big up the guy who found this out, very nice write up,just sorry i never put both in at the same time as it could have saved me a bit of stress.
http://mkiv.com/techarticles/front_end_popping_noise/index.html