pontiac info

hey guys. does anyone know what transmissions will fit or bolt up to a 59 389 motor. like a 200r4 or something? I want to upgrade the trans and not sure what will work directly and clear the X frame. any info??

Nothing will directly bolt up. You can get adapters from transmissionadapters.com I think it is. You can use their kit to adapt your 389 to newer chevy trannies. Starchief1959 has done this upgrade. Maybe he can give you specifics.

Automatics require an adapter kit. Manuals (I'm pretty sure) can use the existing bellhousing for other GM manual transmissions.

For the adapter kit the best bang for your buck is to pick up one from Wilcap. This will allow you to bolt up a modern GM transmission whether it be TH350, TH400, 700R4, etc. You need to supply a specified starter you can pick up from an auto parts store. Driveshaft will need to be cut and a tailshaft mount will need to be fabricated/modified. Linkage will need to be modified. I also ran all new cooling lines and installed an external cooler. Total swap out cost me about $1,500 with me doing all the work myself. Cost breakdown is as follows....

TH350 transmission - $300.00
Torque Converter - $166.90
Valve Body - 122.88
External Transmission Cooler - $61.88
Adapter Kit & Flywheel - $513.00
Speedometer Assembly (Junkyard) - $24.00
Linkage Assembly (Junkyard) - $8.00
Vacuum Modulator - $20.00
Slip Yoke - $20.00
Cut & Balance Driveshaft - $83.00
Cooling Lines - $30.00
Tailshaft Mount - $10.00
Dipstick (Lokar - and waste of $$$) - $92.00

If you want to switch to a GM manual tranny you can use 58-60 for sure and I've had a guy measure his 57 bellhousing and it appears to be the same also.

What's wrong with the hydramatic?

starchiefsgirl wrote:

What's wrong with the hydramatic?

I switched because with the Tri Power I've got too mutch torque and kept breaking fluid couplings. Had to pull the transmission apart 3 times in less than 5,000 miles. On the 4th time I said forget it and did the switch. Not even driving that hard on it, no racing, no neutral drops, etc.

WOw, I wonder if that was a problem when these cars were new???

I've been told by a lot of "old guys" this was a fairly regular problem and one of the reasons they dropped that transmission so fast. I think it only ran 2 years. I do however know a guy with one of these built for drags by B&M. He has it in his basement. Too bad I didn't know about it before I did the swap.

Is it a "Hydrostick?" That was my original plan for my car. Find an old school B&M guyu who would build me a hydrostick. I figured that was going to be way too hard so I just went with a Muncie. haha

I believe so. He's got tons of rare and one off parts from back in the day. Cool guy to talk and listen to.

Just a different personal experience with the 1959 Hydromatic: I owned a '59 Bonny Tri-power from new in 1959 through 1961, put 60,000+ miles on it, and drag raced it often. Never had any trouble with the transmission.

That's sweet! Got any good stories?

4896 wrote:

Just a different personal experience with the 1959 Hydromatic: I owned a '59 Bonny Tri-power from new in 1959 through 1961, put 60,000+ miles on it, and drag raced it often. Never had any trouble with the transmission.

It wasn't a guarantee problem, but one of those it works or it doesn't situations. For some reason that fluid coupling was a problem spot on some of the transmissions and would just give out.