Exhaust size for 5.7

I'm doing a Eagle swap into mt '73 AMC Javelin and am currently looking at how to route exhaust under it before I finish up my trans tunnel. I'm using OE SRT shorties and they measure 2.75" ID. Would 2.5" be adequate or should I go 3" back to the mufflers and 2.5 tailpipes? I'm going to have to use oval pipe since clearance is an issue. This is a street driver used for long hauls so wringing every bit of hp is not my main concern. Thoughts? Suggestions? Thanks.

Im a min 3" guy. I would put 3" on a lawnmower

If you're staying with stock manifolds, I would leave it as 2.5".

I'd do the 3.0 to the muffs , then 2.5 after that , and put some straight through offset muffs in the tail pipes if you want it a little quieter .
And some sort of balance pipe is a must , but that's just my opinion .

My .02 is 2.5in with an X-pipe 2.5in tail pipe,
3in no X-pipe, 2.5 tail pipe

Thanks for the opinions. I'm going to go with 2.5" X pipe system. Getting 2.5" tailpipes in there is going to be tuff but it will happen somehow.

How well do the SRT shorties fit?

The right side fits perfect but the left is hitting the starter. The car version swings away from the block further so I have a pair of those on the way to see if that will work. I'm trying to avoid the cost of special headers. I'm having to use a 4L60E trans so there's an adapter in it and it makes the starter stick out slightly further than it did on the 518. I couldn't get the 518 to fit in the tunnel with the Hemi like it did with the Magnum I had in it.

I picked up a 3' length of 2.5" pipe yesterday and with some drive shaft tunnel "massaging" it will fit, abet very tight. A tight X pipe should fit right behind the X member.