All good info gents & thanks. 1. The exhaust manifold had a couple of cracks and when it was removed, it fell into 3 pieces. 2. I was told by someone on the forum, that with the headers & a twin system, the sound was great. Nothing like being a 75 yo larrikin! 3. As I live in a pretty warm area of Australia, I rarely see temps below 5 C, but regularly see 30-45 C. 4. The idea of some copper pipe wrapped around the manifold sounds good to me, so that looks like the way I will go.
