Just rebuilt a 394 engine and reinstalled it in the car. Transmission now shifts from 1st to 3rd by-passing 2nd. Any idea why?

 

Did you adjust the throttle valve linkage on your 4GC carburetor per the factory service manual and use the recreated OE tool? If not, your transmission won't shift right.

20+ years ago I rebuilt the Slim Jim Rotohydramatic in my 64:98. I never set the throttle valve correctly. I even tried to go to an Edelbrock carburetor for a time. I finally sold my 64 after I got out of the Army. It slush box shifted for at least 10 years.

 

Thanks. Since we put on a dual Quad set up it wasn't connected. We'll try and get it attached.

 

You still have to fabricate a throttle valve rod linkage that will work with the dual quad carburetion and then adjust it for correct transmission function. Turnbuckle style linkage rods will work.

Steve Westlake in Canada, @Oldskeeper here on CO, makes the TVR adjustment tool. www.jaswest.com

 

You're going to have to do some real "engineering" on your dual carb linkage to get this transmission to shift properly.
What you're looking to do is to set the linkage so that the throttle arm on the transmission is all the way forward against the internal stop when the throttle is at "curb idle" ( choke off).
And it should come all the way back against the internal stop when the throttle is wide open. Good luck.

 

Good luck setting the throttle valve linkage for your dual quad carburetors. FWIW, Oldsguy (my father) and I were never able to get that Edelbrock carburetor to shift right on my 64 98.