Transverse muffler to single outlet

I'm considering options for the exhaust on mt '91 MR2 non-turbo.  I would like to build a system that is lighter and more free flowing than the stock dual exhaust muffler, mostly for street-class autocross and occasional track days.  The stock system has a 180 degree bend into a large transverse, dual outlet muffler.

In order to eliminate the 180 degree bend, I'm considering using a muffler that has the inlet and outlet on the same side, similar to the type used in Corvette C5's.  There are only a couple options of universal muffler (Dynomax, Flowmaster, and Magnaflow) that have this configuration, but I'm wondering: can I just weld one outlet of a transverse, dual outlet muffler shut and make it into a same-side inlet/outlet muffler?

My Esprit (RIP) was in and out on the same side. The in and out on the same side mufflers are going to be different internally than the in on one side and out on both sides.  Welding up one outlet is going to cut your flow.  Just get the right muffler. 

I have a couple of NOS in an out on the same end mufflers.  They were mounted transverse on some old Nova and F-body GMs.  I'll see if I can find them and get you a picture if you are interested. 

In reply to Benswen :

When I ran a 91 MR2 in ES, I had a band clamp on the pipe just before the stock muffler so I could just remove the whole thing and put a really short tailpipe in its' place- my thought was that the weight savings were worth the horrible tractor sounds of an unmuffled 5SFE.

If there is room, the C5 Z06 stock rear mufflers are just about perfect.  Super light, free flowing, and somewhat available.  

93gsxturbo said:

If there is room, the C5 Z06 stock rear mufflers are just about perfect.  Super light, free flowing, and somewhat available.  

There is room, although C5 ZO6 mufflers tend to be rather expensive.  I had considered just modifying C5 mufflers.

Flowmaster 842580

Magnaflow 14210

Both available for @$140 and inletand outlet on the same end.  Seems pretty reasonable for not having to muck with it, especially if you were looking to buy a muffler anyway. 

Not single outlet, but there's this option from Vibrant and maybe others:

PN 10632, 10633, or 10635 depending on size. One inlet on the side, dual outlets on the ends. Saves the 180.

Then there's this from Flowmaster. Same idea, but single outlet:

PN 8425461. Much cheaper, smaller, hopefully lighter than the Vibrant above.