crainialsludge

I have a 64 Dynamic convertible that I love but i can no longer deal with the tranny issues. I would like to link a turbo 350 to the 394 via an adapter kit which is readily available and doable. My question is, are there any body mods that i have to do in order to accomodate the new tranny? I was told that I may have to install a new tranny tunnel. Anyone out there done this before? Thanks!

Tedd Thompson

Crainilasludge,

I think you will have to cut the tunnel some .Back in the 7O's I helped a friend put a dual coupling hydromatic or maybe a jetaway in a 63 holiday and we had to cut some to keep it from rubbing. They called it a slimjim for a reason. I feel your pain about the slimjim,my 63 was a gem except for the transmission.It never shifted well to begin with and after a rebuild it was even worse,no one could adjust it correctly and that was only 12 years after they quit making it.

crainialsludge

Thanks a lot Tedd, the more info I'm gathering is indicating that cutting it up seems to be the route to go.

KQQLCAT

I did a swap with a TH400 from Ross Racing and I didn't have to cut the tunnel. I have posted the swap on this section just scroll down a bit to see.

Slash

KQQLCAT, what is your reason for choosing the Th400? Why not the th350 or 200r4, 700r4(something with overdrive? Could you hook up a 4L60e to a 394?

rocketraider

Brute strength. A 400 is a hard tranny to kill.


4L60E would have to have a controller to work. I think that's why most people stay away from those in old cars.


I have never understood why Olds went full-boogie on the Slim Jim, even in Ninety Eights and Starfires. Pontiac used SJ in Catalina/GP but the Bonneville and Star Chief got the Super HydraMatic (Jetaway in Olds-speak) and Cadillac never fooled with the Slim Jim. A Pontiac SuperHMT tunnel doesn't take up much more floor space than the Olds Slim Jim tunnel, but Olds being Olds in the 1960s...