Just watch when removing the standard manifold, chances are its never been off before and pieces of the head can come off with it. Especially at cylinder 3. Look for any cracks in the head and scrape out the carbon from the ports aswell.
Yeah they only made like 25 sets of each size. Rotas are mass manufactured copies, no other way of saying it. Nice build by the way man, thinking of going down the same kinda route with mine.
Yeah i think you can, deffo worth doing as there is a substantial amount of shit you dont really need behind there. Removed the heater matrix and housing too.