Hello,
I have a 98 xj
I'm trying to piece together all new exhaust. Starting with the manifold.
I think I'll go with Walker aluminized steel for most of it, unless someone really convinces me it's a bad idea.
I don't need anything fancy. Not looking to upgrade.
I'm looking at the omix Ada manifold with expansion joints.
I'll put a list here of what I'm planning on ordering so far. If there's anything that is obviously missing, please let me know.

One thing that has really been holding me up is trying to figure out what size and diameter I need. I think I have most of it figured out... But in particular, one confusing thing to me is the outlet from the manifold to the inlet of the front pipe.

The omix Ada says 2.5 out and the Walker front pipe says 2.75 inlet.

Current list with diameter spec
Omix-ADA manifold
Outlet 2.5

Graphoil donut exhaust pipe flange gasket

Aluminized steel front pipe
Inlet diameter 2.75
Outlet 2.5

Walker Ultra Direct Fit Large Oval Body Catalytic Converter
2.5 inlet
2.25 outlet

Walker Muffler Sound FX
Inlet 2.25
Outlet 2.25

Aluminized steel exhaust tail pipe
Inlet 2.25

Rubber black exhaust insulator

Steel rubber exhaust hanger

I am getting two new o2 sensors as well

So my main question is about that manifold outlet to front pipe inlet.

And secondly, just any last words of advice.

Thanks in advance
Cullen