garlandl

I have a 1966 Cutlass with a 330 engine and a two speed Automatic Jetaway transmission. I want to upgrade to a three or four speed tranny, can anyone give me some insight on what options I have. If I buy a TH350 to install does it have to be a certain year, or will any BOP TH350 work? Any help would be appreciated. Thanks

joe_padavano

Any short tailshaft TH350 is a bolt-in (and is a popular replacement for the Junkaway). There are two issues you'll have. First, your stock shift quadrant will only have two detents for forward gears, so you'll only be able to manually access drive and second, not first. Second, the TH350 uses a cable kickdown. You'll need to get the bracket and cable from a mid-70s Olds to connect the cable to your carb throttle lever.

Oldsmaniac

You can also use a short tail Turbo 400. If the car has column shift you can get the p-r-n-d-s-l indicator from a 67 442 column shift car as the dashes were pretty much identical. Also I believe the Vista Cruiser in 67 had the Turbo 400 trans as an option but finding parts from one of these would be rather difficult. The Turbo 400 doesnt need a cable like the 350 trans. Note you will also need the yoke and possibly the (driveshaft?) from the 442 as the Turbo 400 takes a larger yoke.

joe_padavano

A few problems with this. First, in swapping from a 2 spd to a 3 spd on a column shift, it's not just the indicator that needs to be changed. There is a shift quandrant detent plate in the column that would also need to be swapped out. 67 columns are different from 66 columns and I don't know if you can just change the quadrant (by disassembling the column) or if you would need to swap the entire column.

Second, while you CAN swap in a TH400, the crossmember must move. A 66 will not have the holes drilled in the frame for this crossmember location since the TH400 was not offered in the A-body until 1967. Note that this is especially a problem for the convertibles, since the trans crossmember attaches to brackets welded to the inside of the boxed frame and for 64-66 cars these brackets don't extend far enough back to support the crossmember in the TH400 (or 200-4R) location.

Finally, the TH400 will require a new front yoke and a shorter driveshaft.

None of these items are insurmountable, but (especially for a 330) the TH350 is as close to a true bolt-in as possible.

Oldsmaniac

Thanks for the details....I wasnt sure what all was involved but figured it could work and look stock while in the driver's seat.

garlandl

Thanks for the info guys...it will make my rebuild much easier

Olds64

TH 350 is the way to go. Especially if you don't want to mess with all the stuff Joe mentioned. If you have alot of money to burn you could always check out these guys once you get the TH 350 in.

http://www.gearvendors.com/index.html

arocars

If you have a floor shifter, you can use a small metal file and file out enough metal to allow you to grab first gear.

joe_padavano

Actually, if you have a floor shifter, Shiftworks makes a conversion kit for three speed and four speed transmissions:

http://www.shiftworks.com/cutlas.htm

gearheads78

All great ideas but the BEST option involves 3 pedals

I will document my TKO 5speed conversion with a factory 4 speed console. Should be in the next month or so.... stay tuned.

garlandl

The car is a stock column shift but I have noticed that I can buy an aftermarket floor shift for around 200 dollars. Would it be better to buy that than trying to convert the column shifter to a three speed?

gearheads78

I am going to be using a column from a 66 Lemans. Who makes the 200.00 floor shift column?

garlandl

B&M offers a few different options for relocating the column shift to the floor anywhere from $120-$300 through Original Parts Group and Year One.