Considering two exhausts for my 1968 911 (US version, no air pump) and would like input on experiences installing and on use; which would you choose? street use, weekend driver for spirited cruising & canyon carving:

1.Porsche Muffler (Sport) "RSR" Style - Aluminized Steel with Black Finish & 50 mm Dual Center Tail Pipes - JP Group Dansk 1620605800

OR

2.Porsche Muffler (Racing 911 R type) Primered Steel (70 mm Dual Tail Pipes) - JP Group Dansk 1620607000

Does the second require modifications to the bumperette/rear license plate panel? Car has a set of headers right now....

any advise or experiences welcome!!

javier mirandes