you may need to put an extension on for stock muffler to clear fuse. not sure. i used pitts to keep in cowl and i didnt have to clean
much oil off.the pitts is definetly louder if that is a consern. performance should be about same either way. you will want to check and or replace pushrods as mine were brittle. i used hardwood dowels from ace hardware and made my own.als replaced clevises
with better. hope this helps. let me know if you have any questions be glad to help any way i can. andrew wisc.