pipe size from collector to tail pipe.

Not sure!!!
More than likely I will go stainless. The car really is in good condition and I have spent 3 years doing pretty much a complete frame up restoration so why stop now.
Plus it will last longer with the weather up here.
I was thinking of buying the elbows and pipes to make my own, I like that sort of thing, and TIG welding is one of my favorite things to do.
It's the time or lack there of for me to get it done right. I have waited a long time and am very close to being done.
Maybe buy steel than make my own stainless next winter.
Anyways that is getting off topic. Size is all that matters isn't that what they say???