[GM Powertrain]

Originally Posted by tom406

I have a strong purist streak in me, but transmissions, particularly 2sp automatics, are such an inhibitor of performance and driving enjoyment, that I’m in favor of substitutions that don’t involve much in the way of tunnel or frame mods. Swapping a 2004r for a PG/Jetaway/Super Turbine 300 is such a transformative modification that nobody can really see if you execute it properly. Also, 2004R gives vintage BOP guys a bolt on transmission options without adapters or anything. It is literally adding a new low and a new high gear to the mix. Functionally this will improve performance more than most bolt ons and make highway driving less stressful on the car (and you). I feel the same way about upgrading steering boxes for faster ratio and better feel. Getting the linkage right and making the gear indicator appear factory is part of the challenge, but also part of the fun in finessing a solution that looks period correct and proper. My friend put a Borgeson power steering box in his 50k original mile ‘67 Fairlane GT because he got tired of fighting Ford external units and loved how the Borgesons drove. He painted everything to match, used OEM style hoses, used a correct Ford pump and even Ford guys don’t notice it unless you point it out.

Agree with everything you said. I'm sure the car will feel like it gained a bunch of horsepower by just doing this simple swap. It's very tempting.