Which exhaust size?

[ArthurRitus]

My supra has I THINK either a 3.5" or 4" exhaust, but its welded on shitty, crooked, and the bottom got grinded bad to where its no longer round,
I have a 3" exhaust brand new i wanted to put on because it looks better, but will it be good to just keep what i have?

heres the exhaust i have, and the one i bought with the sound supressor on and off

 

[Datsrboi]

To me an exhaust tip means nothing if the pipings are small.

 

[7Mboost]

I would just get it welded right, I wouldn't downsize piping unless you needed more back pressure the question comes down to what are your mods?