I hope you have the original 2.6 I was wondering if a 2.3 had been swapped in, not out of the question by any means.

Anyway the order I'd do things in would eb to do a full tune up and make sure everything you already have is in good working order.

Then I'd do the cam.

Then do the exhaust. If you want, seeing as you already have exhaust issues, either fix the exhaust leak, or add the header to fix it. Whichever.

All I know is that an exhaust leak can dramatically hurt performance. I blew out a header gasket on the way back from wheeling and had no power whatsoever.

Joe