Jerry,
Many thanks for your thoughts but based in the UK trying to get hold of a 250 engine might seem a little difficult and this 230 runs as sweet as a nut, i have been told that there is a twin exhaust manifold that can bolt straight onto mine allowing the gases to escape quicker will that help, i really dont want to spend to much lets say about £500, exhausts are not a problem as i get them made out of stainless steel for no cost.
Your thoughts please

Mark