[MLMike25]

I have an auto 93 notchback with an offroad MAC h pipe and flowmasters (no cats). Will these longtube headers work or do I need a certain type of header?

They are Headman Long Tube headers:

http://i7.ebayimg.com/05/i/06/1a/3f/1f_1_b.JPG

 

[meangreen92]

You need either shorty replacement headers, which will work with your existing parts. Or else you will need the corrosponding H-pipe for the longtubes. With longtubes, you really want headers and an H-pipe from the same manufacturer. With shortys it really doesn't matter.

 

[GhostDog 5.0]

As meangreen already stated, if you are going long tube, you need to get the correct mid pipe. Staying with the same brand is the safest way and usually cheapest.