1 3/4" Primaries on Long Tube headers. What Are My Choices?

[Hemissary]

Simon, that in bold red begs the question: Are the ARH and Kooks high flow cats relatively the same performance wise and length of service?

Hmm...I know that Kooks offers two versions. After the higher performance version became available, I called and pressed hard for numbers prior to purchase. After R&Ring the normal versions, the higher performance units did not equate to a measurable / repeatable delta on the dyno over the normally offered versions (no surprise really - same casing...R&R again and sold them for darn near what I paid). As far as longevity; after four sets on different apps, they all are still in service. On my Magnum, I had the CAT-back off during a head swap a while back. I always peer into the CATs with a bright LED / boroscope looking for debris (you'd be surprised) and cell blockage. They were clear - like new.

ARH CATs; I would definitely phone and ask who contracts to them for their systems.

[Craigslue]

Hooker does make 5.7 & 6.1/6.4 catless mid pipes for their headers, they butt up end to end and use a coupler that fits on the outside of both. Not sure if you could add cats or not due to the length of the headers. The collectors extend all the way to the transmission mount/crossmember not leaving a lot of space to fit a cat before the mid pipe bend.
Hooker BlackHeart 70802302-RHKR Long Tube Header Mid-Pipes (holley.com)

Here is a article with some pictures Gallery: Short vs. Long Tube Header Performance With Hooker Blackheart - Mopar Connection Magazine | A comprehensive daily resource for Mopar enthusiast news, features and the latest Mopar techMopar Connection Magazine | A comprehensive daily resource for Mopar enthusiast news, features and the latest Mopar tech

Here is a video installing hooker headers and exhaust. Hooker Exhaust Install - YouTube