RE: Questions regarding my first speed delta
After e-mailing to Bob (bob27s) I tried a JettStream muffler. Now I have 3 of them. For many years I ran tuned pipes. I ran engines on the bench and tached and trimmed the header time after time. It sure is a lot easier to bolt on a Jett. If you have an OS .46AX, get the Jett for it. Use a 10-7 or 9-8. They don't turn as much as the older FX, but will turn a bigger prop. You'll probably gain 1500 rpm with the Jett.