Thanks guys,you are all great helps.So the best bet is to remove the rear APU and graft the tail light back on,it catches stuff like kerbs when ascending or descending also it makes the tank not look right in my opinion.I've found a seller on ebay in Poland who has got the Bulldog and Pershing metal gearboxs with motors and long output shafts for £16.99 plus £6.95 postage to UK so i'll go for one of them,next would be propulsion to make it more controlable,it'd be nice to keep the HE sounds and have HL drive speeds but I don know if thats possible,i'll just source the S+S boards and a controller and go from there....