LT1 Exhaust size?

[2tuff4u]

Im going to order an exhaust cutout for my car but im not sure witch size to get. I figure I will have the shop throw a new muffler and tips on as well. So, what is the outlet size of the y-pipe? And what size cutout should I order?

[WS6SP33D]

If it's factory Y and i not mistaking it's 2 1/2" that runs into the over the axle pipe. I know most aftermarkets i have installed are 3"

[2tuff4u]

Thanks! Went ahead and picked up the 3" cutout.