TRS 330 454 Power upgrades. I have twin 454 on my 1981 30' formula. I am looking to get some more power. I am interested in little ideas such as set timing advanced, run synthetic oils, etc. I read that the penut port heads area killer and that they must be changed first to have any chance at power. What are good ecomical heads to run and will 8.1 Exhaust manifold work well/save weight over the old bobtail iron ones?