[SmokeyWren]

All "early" '99s had a diesel catalytic converter. All 2001-up 7.3L stick shifters with 275 HP had a catalytic converter. None of the other '99-up 7.3L PSDs had a cat.

Your best bet is to have a muffler shop do the install. They can cut off the cat from the old system and install it in the new exhaust system. If the cat is not stopped up with soot, then it won't affect performance. But a good muffler shop will probably charge around $75 to do the deed.

If the cat is stopped up, you can buy new ones to replace it with. There are even diesel cats with 4" inlet and outlet on the market. Do an internet search on "diesel catalytic" and you'll find them. But your $300 budget just got whoomped on. :read: And pay attention! Diesel cats are different than other cats.