I am talking to Carquest right now. He has the m090544, but can't find the 86131m part number.
Thanx.

 

THe mo09544 is the donaldson and the nelson is 86131m.

I got the donanldson muffler myself setting at the house ready for install.

I got it from ryder fleet sales.

http://www.ryderfleetproducts.com.

Total cost with shipping was 83.00.

 

Thanx Powerdually. I don't know why I am a little out of it on these. I guess they are both 51 inches, 4 inch inner diameter, with no obstrucitons all the way through-not getting smaller than 4 inches at any part. Should I diffenterate between either when I find somone local who has one? My local Carquest can get the m090544, but does not carry any Nelson stuff. My muffler guy was the same deal. Ryderfleetpriducts.com carries both brands but does not list these numbers. I should call them tomorrow.
Thanx.