1966 Cutlass

Hi,
I have a 1966 Cutlass Sports Coupe with a 330 ci/4 barrel.
>What model jetaway do I have?
>My servo cover is missing. Can I get one?
>My car has been apart for 24 years. I am getting ready to attend to the transmission.
I have 62 K on the car. The car was never beat on. The transmission worked fine before the project started. I am the second owner. Will the friction plates be bad from sitting that long or is that not a problem?
> At minimum it was suggested to replace the front and rear seal along with a new pan gasket. Plus a new trans fluid tube bottom seal. I am going to order a banner rebuild kit from Rock Auto. The two brands to choose from are Pioneer and ATP. Is one better than the other?
>Is there a good rebuild manual for my transmission? I did not see one on the ATSG site.

Thanks for your help.

lunaboy

unless you want to be a purists i would scrap the Jetaway and spend all that money and time with something better ,,, if you are removing it anyway and Doing all that work go turbo 350 3 speed. Not kidding, i just (yesterday) gave one away and going with a 3 speed with mild shift kit.

66_Jetstar

I have a switch pitch jetaway in my Jetstar. its a cool trans. Undoubtedly its an outdated two speed but it still serves it's purpose just fine. Most folks never heard of a switch pitch so it's fun to talk about.

My car sat for 20 years. I swapped the filter (after driving it for five years) and that was it. No leaks. I wouldn't make a project out of it.

joe_padavano

What are you planning on doing with the car? If all you plan to use it for is to drive to and from cruise night, the effort to upgrade the trans is likely not worth it. If you plan to actually drive the car, the extra gear of a TH350 will make it much more enjoyable.

1966 Cutlass

Joe,
You and another member suggested the TH350 3 speed as a nice upgrade from ST-300. I am not opposed to making my car more drivable. I already ditched the drums for disc brakes for the same reason. Is there anything I need to be looking for when searching for a turbo 350 transmission besides that it came out of a Oldsmobile, Buick or Pontiac? The Chevy version won’t match up on mounting, correct? Is there any other things involved in the trans swap like shift linkage or driveshaft length? I can get over the dash transmission indicator being a little wonky. One last question. My mechanic buddy asked if a 700R4 would be a viable swap? This would give me overdrive. Same questions on that. What obstacles would I have to overcome for a swap. Thanks for letting me pick your brain(s). This group is awesome.

John in Lowell,Indiana
​​​​​​1966 Cutlass Sports Coupe

1966 Cutlass

Aw man, timing is everything! What did the mild shift kit bring to the picture? Does it let it hit a higher RPM before shifting?

joe_padavano

The short tail TH350 is nearly a bolt-in for the Jetaway. Driveshaft, crossmember location, e-brake cables all stay the same. The only issue is connecting the kickdown cable. On the 1069-72 Cutlii this cable came through the firewall and connected to the accelerator. That's not an option on the 67-older cars, so an aftermarket cable and brackets are needed. Unfortunately all the aftermarket brackets are for Holley and E-brock carbs, not Qjets, so some fabrication may be required. If you can find a late-70s Olds factory bracket, that's a bolt-on.

The 700R4 requires an adapter plate, custom crossmember location, and custom driveshaft, in addition to the TV cable connection. The 200-4R is a better choice as it also is the same length as the Jetaway and TH350, so driveshaft remains the same. The 200-4R does move the crossmember back to the TH400 location, which won't be drilled on a 66 frame so you'll have to drill the holes in the lower frame rail. Moving the crossmember means that you'll need to change the front and intermediate e-brake cables to the ones for a 1967 442 with TH400, but those are readily available from RockAuto. And you still have to connect the TV cable. We did this swap recently on a friend's 69 F85 and Lokar cables are quite nice. Both the 700R4 and the 200-4R should internal mods to live behind even a 330.

JohnnyBs68S

My biggest gripe w/ the Jetaway in my '68 (non switch-pitch), was that it effectively had no 1st gear (WRT a TH350 for example) making is slow out of the hole. But once it got rolling, w/ the 2.78 rear it would hit 70 indicated in 1st gear before up-shifting at "hard" WOT (downshift switch engaged), which pretty much levels the playing field from a roll. I remember leaving my buddy's '73 350/TH350 Firebird in the dust on an entrance ramp once.

So, the Jetaway is OK for just cruising, but if you want to have fun, more gears is where its at.

joe_padavano

Effective first gear with the Jetaway is 4.837:1. (1.74 first gear ratio x 2.78 rear axle). The switch pitch would increase that off the line.
Effective first gear with the TH350 is 7.006:1 (2.52x2.78)
Effective first gear with the 200-4R would be 7.617:1 (2.74x2.78)