1970, 134f, Exhaust Head Pipe Diameter?

Replaced my head pipe a couple weeks ago. Came from eBay, a new old stock piece.
Went on, ok, fit well. Hung an old generic, cherry bomb style muffler behind it, turned it down,
just before the axel. Head pipe measured 1-5/8 od. The old, rusty,bent up,short piece that I replaced
It with was only bout 18 in long with some flex rigged to it for a temp exhaust,
The old piece was larger diameter than my new pipe. Bout 1-3/4.
Is their more than one size, I found only one size when I ordered mine?
Reason for asking, it seemed to have slightly More torque off idle before, but better top and quieter now?
Both were similar length . Old pipe muffler was 2in exit, new muffler 2-1/2 exit?

 

Any idea what the larger pipe came off of?
A 134 in a ?