Converting to a 4-speed

[DeucePhaeton]

My son is the Jetfire owner and we are converting his car to a 4-speed. We bought all the parts we needed for the driveline from a guy parting a 4-speed Cutlass. Now comes my question. The trans tunnel on the 4-speed Cutlass is different that the trans tunnel on our Automatic. The 4 speed is bigger. It appears the factory put a larger tunnel in and cut the old out. The 4-speed tunnel was spot welded to the old and the original was cut rather crudely and seam sealed. Any input on the subject? :blink:

[kid442]

Deuce,
I have converted two 63 Jetfires. I have just acquired back my first car. I will attach a few photos. The car I have now I just screwed the 4-speed hump in place. The second car I spot-welded it. I could tell the difference between the two cars when driving. If you need any help or information please feel free to give me a call.
Good luck and keep in touch.
Ken Dennison
732-870-6964
kid442w30@yahoo.com

[DeucePhaeton]

Thanks.
That’s the parts I have. Spot weld them in is the plan then.
I’m sure glad I noticed the trans tunnel was different when I bought the 4-speed stuff. Could have been a disaster had I not seen it. Would have been a lot more work to make a piece. 😛

[62oldsf85]

Don’t know if you’re still doing this, I ended up using a 62 Nova shift hump in mine. I didn’t notice the difference in the tunnels until I tried to put the trans in for a dry fit, and then had to cut and weld. It works just fine.

[macf85]

I made this modification in the same way that kid442 did. I was lucky enough to find an original ’63 Cutlass with the entire 4-speed setup still intact. I got the bellhousing, clutch, flywheel, pedals and clutch release mechanism, transmission and the partial floor pan/transmission tunnel. The factory did cut out the auto. trans. tunnel on the assembly line and welded in a partial stamping to accommodate the trans. shifter. You’ll probably have a hard time finding an original car that was a 4-speed though.

[DeucePhaeton]

Actually I found a complete 4-speed drive line out of a wrecked 62 F-85. Bought it from the flywheel to the rear end. Pedal assembley and linkage with trans hump too. Bonus! Thanks for the reply.

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