I have a sierra exhaust gasket for sale, just give us $10 and I will post to you.
Also have a custom G13 inlet flange lasercut from 10mm steel. I made this up as I was originally going to make a custom inlet manifold, a more efficient one for a turbo, never got around to it. Want $50, can post if needed or pickup in Glen Waverley. It is portmatched to a G13 head too, my head at least, should be pretty damn close to yours, I found the stock ones were way out. You can see the coolant passage holes there too.
Have a set of Top Gun spark plug leads for a G13A, all new never used, $20 inc postage (will post without box). Part number is TG4118
