Originally Posted by F150sarebeastI have a 1989 f150 5.0l all stock exhaust and engine and I got a thrush welded muffler and it doesn't sound right. I know they sound similar to flowmasters, and I know the muffler isn't damaged because I had it on a different vehicle and it sounded good. It just sounds like I didn't put anything on at all.
I know it seems stupid and that only a dumbo would do this, but ive done it before haha, maybe the muffler is on backwards? Other than that pipe diameter makes a sound difference too. If that stuff doesnt work you can always make it tailpipe deletes! Thats what I did to my flowmaster 40!