Since you are going to do a lot of work and investment, would you consider a 261? It should be a direct replacement. I did that and was very pleased with the results. I thought it was a better investment than the old 235, and way stronger (with the dual carbs, 848 head, dual exhaust and cam upgrade). Nothing wrong with the 235 choice either, just something to consider if you are going to do all that work.
don
