Replace 1 7/8" pipes by 2 1/4" on a 6 cyl.

UPDATE:
Finally, the front pipe was not 2¼ except for a part ahead of the catalytic converter.
Now received 2¼ everywhere, the cata was sold to partially finance the operation.
Yes, we have a difference! Can feel more torque, acceleration with less effort.


Dart/Valiant said
Looking under my car and taking a few measurements, I saw that I have a 2¼ O.D. front pipe. which narrows to 1 7/8 where the catalytic converter is welded. Could we start from the front pipe and continue this up to 2¼ all the way back?

Do you see any side effects to doing this? I would also remove the catalytic converter, (legal for such an old car where I live). Does this have any significant value?
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