Heat affects the coolant header tank and the turbo oil return. A turbo beanie will sort out the header tank issue and you'll need to use heat shielding over the oil return pipe. If you are taking the manifold off you should replace all of the fasteners with studs. The barra heads strip very easily and in some cases will strip a thread just by undoing a bolt. I haven't had any issues with weight hanging off the head. Get 2 O2 fittings welded to the dump so you can run your nbO2 all the time and fit a wbO2 when needed. A 2 piece dump makes life a lot easier for fabbing, install and removal down the track. If you decide on running a custom 4 inch exhaust, make sure to use 1 muffler at a bare minimum, straight through is miles too loud.