I think hammers is the same size as the stock pipe from the cats back.

Now looking at this image I was able to track down of an 05 rams stock exhaust, the stock cat appears to have a 3" inlet and a 2.5" outlet.



So if I can open up that outlet it be perfect.

 

Your gonna have a real hard time expanding stainless.

 

Another for the outlet side where the rear O2 is located

 

Also, the stock manifolds are 2.5" so the cat must be 2.5" in and out. Or for older models 2.25"in/out

i doubt they are 3" in. No reason for it.

 

I know the outlet is 2.5, but the inlet in the pictures appear to be larger than 2.5". Well guess I'll find out tonight.

 

Anyone know what gauge wire is used for the O2's? or if autozone or napa ould have an O2 extender wire?

 

The wire should be 18 or 16ga if I'm not mistaken. They may have pigtails which will save you from cutting your harness as long as they have both male/female ends.

Also, did you read my post above? Your gonna have a hard time expanding that stainless. You will likely have to heat it up so much that the rubberband will melt on the cheapo tools that are available to us. Stainless is really hard to expand even just a teeny bit much less than 1/2".

 

seriously bro, you're asking for a lot more trouble than what it's worth. just use the sizes that it is. whatever restriction that couple inches of extra pipe is going to add is not worth all the trouble.

 

Well I guess I can use the adapters and weld them on, since I got rid of the cutout space really isn't an issue now, I'll just cut off the dump pipeand fit it to what I need.

I had a few ideas as to how to get a half inch out of it though by cutting reliefes in the pipe before trying to expand it.