Auto to 4 speed swap, need help.

[Devilbrad]

Hey all, I just picked up a 66 Coronet, 383, auto. The trans is trashed, so I have decided to convert to a 4 speed. Anyone done this on these cars (I believe the 66-67's have a unique pedal setup)? Any input would be appreciated. Also I am looking for any and all parts to do the conversion, so dig around that garage!!!!

Brad

[Devilbrad]

No ones done this?????

[Ausydad]

Many people have done this and I'm currently trying to gather the last few pieces needed to complete mine. Your looking at changing the tunnel hump for room for the shifter. Switching the flex plate for a flywheel, switching to the 4 spd crossmember and mount, adding the "Z" bar and connecting linkage (best to look at old "Direct Connect" literature for diagrams), switching to the new pedal cluster (I'm not sure of the setup on B bodies), and removing the shifter from the steering column or changin to the floor shift type. Your driveshaft is supposed to work without changing it (unless you have the old cast iron type trans with the bolt on yoke instead of the slip spline). For the B body, the best I can tell you is to look at 4 spd cars at the local shows, look for DC literature, talk to your local trans shop guys, or search the archives here for info from more experienced B body guys. Best of luck to you!

[Stoga]

One thing for sure, check your 66 383's crank flange for the pilot hole being drilled deep enough! I ran into this years ago, when I spun a rod bearing in my old 70 roadrunner. Thought I would just toss a used 383 in it to keep it moving. Turns out the hole wasn't deep enough for the input shaft of the 4 speed to fit into the engine far enough! Caused myself a bunch of heartache, and ended up just rebuilding the 440 stock, and sticking it back in.
Some originally automatic equipped big blocks, didn't have the crank flange drilled for the pilot shaft, be sure before you get into the same mess I did.

[Doug Wilson]

If you need specs to get the hole machined, let me know and I'll mic mine on the 440.

[Devilbrad]

Cool, thanks guys! I wont be doing it anytime soon, I was aware of the crank pilot hole so that wont be a problem. Starting to try to gather pieces. Does anyone know if a 65 4 speed trans will work with my driveshaft? Apparently the trans in question has a bolt on driveshaft so there is a flange on the output shaft. Will I need to change to a later output shaft (tear down trans)? Are the gear ratios differnet in this trans as compared to say a 71 trans???

Brad