What you need to do is adapt the muffler to the stock header pipe.

gort, i'm probably going to look for a different muffler around here... none of the bolts line up, and that is my main problem right now.  also, when i put the muffler onto the head, it won't slide all the way down.  for now i painted my stock muffler black, and will have pictures up tomorrow when it is dry!

Twdy, I highly recommend you stick with the Dyna muffler and make it work.. you will not find a better one for $100, and you got this one for free?    You've been given some good advice here and I can't add much, except that a couple of washers will help the rear mount and muffler rail go from near-perfect to perfect alignment.  It is true that the header collar will not butt against the muffler.  There is about an extra 3/8" of header behind it that doesn't matter, especially after you fit a heat shield.  It's also true that you should put some copper shim stock between the header and mufflers to make the english and metric stuff match diameters.  It also helps to cut a couple more relief slots in the muffler (go from 2 to 4) and put a washer behind the lower mount of your front heat shield, loosen the header collar at the cylinder and swing the header outward slightly.

I know this sounds like a pain, and the "it's a direct bolt on" claim is somewhat exagerated. But gee-gads! I just spent almost $400 on a whole exhaust system specially made, artisan-welded and all that for another bike, and it didn't fit as good as the Dyna on the Savage.  You gotta tweak stuff no matter what you do  

Yes, there seems to be a variety of mufflers, and this matter has been discussed in the past.  You must get exactly the right HD muffler, and I've given you what I think are the the serial numbers on mine.  Again, get the right one, because it bolts up EXACTLY to the Savage, as I've said before.  You have to wiggle it around a little, and firmly push it onto the header pipe, but if you take your time and use the right HD muffler, you don't need to cut, bend, file or weld or fabricate anything anywhere, except for the use of a copper shim around the end of the header pipe. The space between the header pipe collar and the mouth of the muffler measures exactly at 5/16", if you push it on right. The Savage heat shield bolted on without modification.  This was an easy install, and it never leaked.

I put a cheap knockoff of a Dyna muffler on mine ($10 @ salvage yard, woo! ).  I put an extension in, because it didn't have the rail mount, and I needed it to get the mounting holes to line up.  I had them put a couple degrees bend, about 8 I think, because if you look at the stock muffler, there's a small bend near the inlet, to make it line up with the hanger.  I also had them spread/shrink the outlet/inlet of the adapter to fit the header and muff.  Worked like a charm, although I went with the really heavy duty clamps to ensure no chance of leaks, the Harley clamps just weren't doing it.  Here's some pics!





Then just slap on a Harley heat shield from a 2 into 1 pipe, and voila!