I have a 73 9114 with what was originally a 1. ? eng. Was told by PO that it was upgraded/ converted to a 2.0 with Weber Carbs. It has no heat exchangers. How do I know which kind 1.7 .8 or 2.0 exchnagers to buy and I know to have a matching muffler. How can I tell what is (prob. rusted on ) on there now.
frijolito

All headers are interchangeable, but not identical. That being said, the 2.0 stainless header flows the best, followed by the stock 2.0 headers.

The only difference between the 2.0 and the 1.7/1.8's is that the 1.7/1.8's roll up at the end. Otherwise they are the same.

\pipe inside diameters are different.....

on the stainless versions by SSI - they were all the same ID

AND, you have to use the 1.7 Muffler and Hanger bracket with the 1.7 "curved end" Heat Exchangers...

Likewise, you have to use the 2.0 Muffler and Hanger Bracket with the 2.0 "Straight End" Heat Exchangers...

Unfortunately, I don't have photos but I'm sure some of the other folks do!