The engine work is reversable and easy to do.Just a matter of barrels and pistons.My Ferracci kit was £750 all in including gaskets.Not sure if teh head work is worth doing,but i have been well chuffed with mine and been perfectly reliable.Fuel set up is only a mtter of putting an FIM Ultimap chip in!You can get it fine tuned later.Timing etc is the same as the 748.Mine went from 87bhp to 105bhp.So basicall a 20hp jump.50mm termis are worth investing in.