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The two fitment problems are moving the crossmember back and clearancing the tunnel. You should be able to simply slide the existing crossmember rearward and drill new bolt holes in the lower flanges of the frame rails. If your Cutlass previously had a TH350, you'll also need the front and intermediate emergency brake cables for a TH400 car, due to the relocated crossmember. The 4L80E actually fits better in an A-body tunnel than the 700R4. It's tight and you might need to make a few "adjustments" with a hammer, but there shouldn't be massive cutting and rewelding.
This article about fitting a 4L80E into a Chevelle applies to your Cutlass also. It shows the tight spots in the tunnel. It also shows the banjo fittings for the cooler lines that really help with clearances.
I'm not a fan of that G-Force crossmember due to the offset and resulting twisting loads. It clearly was not designed by an engineer, although in the case of the car in that article, it's a convertible with a boxed frame so sliding the crossmember back was not really an option.
As far as the nuetral safety switch on the manual shaft, I’m guessing the trans controller will determine if you need it. Some transmission controllers might use the internal pressure switch manifold to determine the gearshift position, others might use the external switch.
What are your plans for a speedometer? The 4L80 has no provisions for a cable driven speedo. I do know some transmission controllers display vehicle speed, so that’s a easy solution. There are companies that offer a modified extension housing to accept a th400 speedo gear housing. There are companies that offer modules that plug into the 4L80 output shaft speed sensor, the module converts the speed sensor signal to drive a motor, which then spins the speedo cable.
Probably the best option (in my opinion) is to have the speedometer rebuilt with modern electronics. It will look stock, but have modern stepper motors to move the speedo needle. Easy to calibrate, no speedo cables or external controllers, and about the same money.
The 4L80E uses a trans-mounted gear selector switch. For OEM installations, that switch is wired to the ECU. Not sure if it can carry enough current to serve as the NSS or not.
There are mechanical speedo tailhousings available for the 4L80E. They aren't cheap, but still probably less than converting the speedo to electronic.
You can also get conversion boxes that take the VSS signal and use it to drive an electric motor to turn the speedo cable.
Just a couple of thoughts. As I mentioned above, I don't understand why you need a new crossmember on a non-convertible. Also, I have a friend with the Shiftworks dual gate four speed kit in his 72. I'm not impressed. Fourth is in the former neutral position, and P,R, and N are all squeezed into the space formerly occupied by just P and R. The right answer is to get one of the unobtanium four speed dual gate shifters that Hurst sold in the 1980s. These are long out of production and go for stupid money when you find one, but they are the proper solution.
The two fitment problems are moving the crossmember back and clearancing the tunnel. You should be able to simply slide the existing crossmember rearward and drill new bolt holes in the lower flanges of the frame rails. If your Cutlass previously had a TH350, you'll also need the front and intermediate emergency brake cables for a TH400 car, due to the relocated crossmember. The 4L80E actually fits better in an A-body tunnel than the 700R4. It's tight and you might need to make a few "adjustments" with a hammer, but there shouldn't be massive cutting and rewelding.
This article about fitting a 4L80E into a Chevelle applies to your Cutlass also. It shows the tight spots in the tunnel. It also shows the banjo fittings for the cooler lines that really help with clearances.
I'm not a fan of that G-Force crossmember due to the offset and resulting twisting loads. It clearly was not designed by an engineer, although in the case of the car in that article, it's a convertible with a boxed frame so sliding the crossmember back was not really an option.
Considering how that mount is on the front end of the V shaped crossmember, and could have been on the back end of a low profiled in that area cross member, they could have at least gotten rid of half the problem.
I've never met people with more chips on their shoulders than welders and industrial techs who don't have an engineering degree and all they do is complain about engineers all day long. They love to say an engineer can't weld; in this case, the opposite is also true, whoever welded that up can't engineer. I'm tempted to walk downstairs and look at a loaded up Sequoia chassis just to purge the demons.
If you end up with a Dominator or Terminator EFI setup, you won't need a controller as those systems are ready to control the trans like they do on modern cars.
I wrote the installation comments that 70cutty copied above from the facebook site Restomod Oldsmobiles. I'm including the pictures that go with that write-up. I'd like to ad a few additional comments not covered in the write-up.
1. I have a GPS speedometer from SpeedHut and it works great.
2. The stock cross member looks like it could be slid back and re-used, however, you will have to put it up on the frame BEFORE the trans goes in. You cannot get the stock cross member in and out with the trans in place. The G-Force cross member is a bit overdone, but it works fine and can be removed while the trans is in place.
3. The Quick 4 controller works great and is fully adjustable. It also requires a tach connection.
4. Shiftworks makes a conversion for the stock console shifter and the dual gate. The manual side of the Dual Gate shifter still works fine with the conversion. Or, you can buy the aftermarket 4 speed shifter of your choice. The B&M Quick Silver ratchet shifter is a great choice.
5. I used the stock 4L80E neutral safety switch and a relay to connect the starter circuit. I also used it to operate the back-up lights (no relay required) See wiring diagram. 4L80E trans, about 3.5" longer adapter plate, 3 bolt flywheel 32" shift cable to clear connections shifter linkage, ARH 2" SS headers 3 bolt lock-up converter trans cooler lines G-Force cross member Holley Carburetor TPS switch trans installed Currie 9", 3.5" driveshaft and 3" Pypes exhaust wiring diagram
Hi thank you so far but whats up with the tourque converter, my flexplate has 3 holes I have seen many smaller 10-11" ones but they have 6 bolt pattern.
I have the early transmission 1993 with the cooling lines more in front is there a smart solution to connect the lines.
And my tranny has the old style of connector is there a way to convert it to the new one to fit the most new style one transmission controller.
Is EZ-TCU or Quick 4 controller the way to go
Sorry for all my questions but with my Olds here in germany there is not much knowledge to ask, so I need really help from you guys ;-)
The truck torque converters have 6 bolts. My flywheel has 3 holes like yours. I ordered a converter to fit the Olds crank and flywheel and allow for the 5/16” thick adapter plate. The
cooler fittings can be changed to AN type, there are early and late thread sizes. Also one fitting has ~2” tube into the trans.
There is a conversion harness you can buy to convert the internal trans harness to connect to the controller.
There are companies that sell complete set ups for your car; rebuilt trans, converter, controller, cross member etc, but they are expensive $7,000-$8,000
To convert the connector GM has a complete internal harness. it's pricey, around $200. GM 24200161. Or if you feel comfortable with wiring you can just buy the plug and splice it in, around $60 and pinouts are available online. Not that hard.
To connect the lines I used banjo fittings LINK HERE to run my cooling lines and convert to -6AN. With banjo style adapters there was plenty of room, I didn't have to hammer to floor. Since you have the old style case, you would need 2 sets of banjo adapters cause you only need the (2) short ones. Unless you can find just the short one, it's a 6AN x 1/4NPS thread.
Or you can buy the adapters like the ones HERE and run 90º hose ends.
