Norcal49, what type of a Dirt Squirt are you wanting to put this pipe on? If it is the earlier (model 96) one with a cast iron cylinder, there would be no need to cut the nut off, as it would thread right onto the cylinder. If it is an aluminum cylinder model, then yes, you would need to remove the nut and make sure the head pipe was the proper size for you exhaust manifold.
dirty-rat, My Dirt Squirt is a 73 model 96 (I think) and does have the cast iron cylinder with the sleeved nut that the pipe slips into. The Torque pipe
is made with what looks like the exact same nut on it but it is a flanged pipe. I've got to take a trip next week but I shall soon find out when I get back. The more I look at it I'm thinking that it may very well go right on but we'll have to wait.
If that's the case, you should consider one of the crush type copper gaskets (PN 542509) between the spigot and exhaust pipe nut. They keep the nut from vibrating off as easily and provide a durable seal so all exhaust gases exit through the pipe as intended.