hi flo cat versus pre muffler effect on power?

[s5uewf]

I'd like to replace my cat. I figure after almost 20 years it
is probably somewhat clogged up.

Being able to remember the first Earth Day, and appreciating
the fresh air, part pf me wants to install a high flow cat.
My question is whether a high flow cat will restrict power
significantly compared to installing a Pre muffler instead.

Does anyone have any factual information to share regarding
high flow cat effect on power versus Pre muffler effect?

Steve - any customer feedback - any chip tuning with a high flow?

Emery