Gearstar GM 4L65E 4 spd Auto behind 390 stroker (318 OE) .... BLASPHEMY!!!!

[VitaMeVas]

**Warning...this thread is currently under construction. I've gotten most of the way done, but am waiting for parts, so I'm starting the writeup.**

The 'WHAT': I'm putting a 4L65E GearStar built transmission behind my original 318 (390 stroker) engine to make it into a 4 spd automatic. The car is a 1968 Plymouth Satellite. Yes, I know about the A518 but they've been hard to find and even harder to find someone to build in Nebraska. Yes, I know about the GearVendor Unit but I didn't want to go that way. Yes, I learned how to drive a stick in my teens, but I wanted an automatic transmission so my wife could drive it when she wants. Having an automatic for my wife also means she's ok with me 'dumping' money into my project. *wink wink* Yes, there are lots of transmission companies out there, but I've heard good things about GearStar from word of mouth and television. I LOVE all mopars, but I'm not a 'purist'. If someone makes an electronic gizmo that allows me to monitor gauges easier/improves safety features/looks 'cool' then I'm all for it. I want my project to look 'old' but have new technology (I usually try to keep the gizmos hidden).

This is the project before when it had the original 3 spd 727 and the front clip from a 1969. I've changed out the grill to a 68 grill but the side markers are still 69.

So....if you're a 'mopar purist' and want to say 'I told you so' over and over again .....this is the thread for you!!! I've had lots of hurdles and problems, but I'm seeing the light at the end of the tunnel. If you've ever considered putting in a 4 spd automatic .....this is the thread for you!! This will let you know what you maybe in for. I'll try and include part numbers of what worked (and more importantly what didn't work) as I go. If you're a troll that just wants to piss and moan ....go somewhere else.

 

[VitaMeVas]

The 'WHY': As stated above, I want anyone else crazy enough to think about this to know what might be involved. But I do write-ups also for me, so I can look back at what I did years from now and 'remember' why I did it a certain way. Also if something breaks (which is darn near guaranteed) where I buried the gizmo and how it's wired. Or maybe if the car ends up killing me in this process .... my kids can know what the hell dad was doing in the garage (boys: 6 and 9). Lastly, I want to drive the car on the highway without the tach humming at 3200 rpm doing 75 mph. I want to be able to do a 1/4 mile for fun (not professional racing) but also have another gear for cruising with my wife/kids. The original 727 3 speed had a 'shift kit' in it and was built for 1/4 mile races only. It would go through all 3 gears by 50 mph despite me changing the rearend gears to 3.55 (original 8 3/4 rearend). It also was leaking from a few places and needed 'attention'.

I dedicate this write-up to a man and his kids who went to my church as a kid. The man has since passed, but my memory of his Coronet has always fueled my love for mopars. Standing out in the church parking lot peering in the windows of the car while the church bell rang (for the late-comers) is seared in my mind and always makes me smile.

 

[Photon440]

It's not that unusual to put that transmission into old mopars, it's a little smaller and fits better than the 518. As for being GM, Dodge even used the Turbo 400 in their Drag Pak Challengers. The TCI 6X Six Speed is also a fairly popular option for our cars.

 

[toolmanmike]

I wouldn't have done it that way but each to his own. The 500 series Mopar O/D's are a bit bigger than the 4L's and are harder to fit in a A body but not by much. I would think a B body would have enough extra room.

 

[radical rob]

Gearstar has a great rep. They will build exactly what you need. Build it however you want. There are enough of them out there you don’t need to restore original if you don’t want

 

[F4R/T]

Not sure why they put gm trans in a drag pack other than cost and convenience..what a shame, a flite was far superior the gm trans..

 

[Photon440]

Not sure why they put gm trans in a drag pack other than cost and convenience..what a shame, a flite was far superior the gm trans..

In the drag racing world, the GM transmission is the one most supported. Ford also used it in the supercharged CobraJet. Dodge probably COULD have engineered a torqueflite to do the job but likely didn't think it was worth the effort for 50 cars.

 

[F4R/T]

Price and convenience win almost every time ...

 

[Jeff Peterson]

Make sure your torque converter stall is less than cruising rpm in OD

 

[VitaMeVas]

WHAT I EXPECTED: I contacted GearStar Transmission and spoke with Ryan (sales rep). I described what I was wanting to do and he explained that I could order a GM 4L60 base transmission with all new internals rated up to 400 hp and waranteed for 3 yrs or 36K miles. I could also build it in different packages or go for the larger 4L80, etc... After much discussion, I decided to have them build a Level III GM 4L65E because the larger 4L80 might require more trans tunnel modification (which I didn't want to do much of). The 'kit' I ordered would come with a torque converter for my application (stall speed 2800) and an adapter bell housing from QuickTime to connect the back of my small block mopar to the GM 4L60 based transmission (QuickTime #RM-9071). Since the 'E' in the title stands for electronic, it was explained that my kit would come with a US Shift Quick 4 transmission controller with a Holley Carb Kit that allows my carburetor to send the Throttle Position Sensor (TPS) signal via wire to the controller (does require your carb to have an electric choke). Also, I would either need a way for my manual speedometer to interpret the electronic signal from the transmission OR have some type of electronic speedometer. I would also need to have my driveshaft modified or a new one built with a GM front slip yoke. I liked the idea of having updated sensors and electronics on my project.... so down the rabbit hole I went. I did need to have my tire diameter specs and my engine hp numbers to help GearStar know what to build. The price tag came back at $6,845 (including freight delivery, core charge, the electronics, bell housing with cover plate, trans cooler (without cooler lines) and torque converter). GearStar does dyno/break in each transmission and includes all fluids. I knew I would need to likely modify my trans crossmember, likely modify my column shift 'Z-bar' shift linkage and order/make some trans cooler lines. Some of the pieces I didn't know I would need were a GM dipstick/tube, transmission metal/rubber mount to the crossmember, and a PC-based Laptop to download/modify and US Shift controller programs (much of my stuff is MAC-based). I pulled the trigger and ordered from GearStar around mid-december 2022.

 

[VitaMeVas]

So.....while my credit card was on fire, I ordered the 'other' pieces I knew I'd need and waited to hear back from GearStar. I wanted to elevate the car safely so I could work underneath it 'easier'. I don't own a lift and didn't want to trust jack stands while I pull/yank on the transmission, etc... I stumbled onto some threads about people making their own 2x4 wheel cribs to lift their vehicles. Here's a link that I based mine off of.



A lot of 2x4's, screws and gorilla glue later .... I had made 4 'wheel cribs' and lifted the car.

I went about unhooking the 3" exhaust from the headers and all the mounts. I wasn't able to take it completely out without cutting the exhaust so I left it 'hang'. Now that I've done most of the work, I will admit it would've been a little easier, but I was able to maneuver the trans-jack and get everything with the exhaust still hanging. I know most people would've cut the exhaust, but it was a really nice full 3" H-pipe exhaust that was well done.

With the car up on the 'wheel cribs' it was VERY stable. It didn't budge a bit no matter what I did and allowed me to use a creeper easily.

 

[VitaMeVas]

THE ELECTRONICS: Knowing that I needed an electronic speedometer took me down a 'rabbit hole' of technology. I decided to go with Dakota Digital because they offered an OE looking display that did more than tell me speed. Here's my original setup.

I ordered part #RTX-68D-STD-X which resembled my original dash cluster. It involves removing the original dash cluster and replacing all the gauges with electronic. What was the alternator, gas, temperature and clock now become the oil pressure, gas, temperature and tachometer. It has 2 small computer screens that can stay black, show scrolling car information, or be stationary gauges that show PRNDL, digital speed/oil pressure/fuel level/engine temp, various sensors, etc...

For me, it allowed me to get rid of the 3 accessory gauges I had mounted under the dash as well as the aftermarket tach that was next to the radio. It comes with a main Control Box (we'll call this DD Box 1) which all the various cluster wires are sent to. You can also order other expansion pieces that can monitor everything from GPS, outside temp, compass, etc.. At the time of this write-up they have since come out with TPMS sensors that are tire specific and will work with all this. Yes......I know .....fancy schmancy spoiled rotten brat stuff. I had to order the GSS-3000 (we'll call this GSS) which allows the information like PRNDL coming from the 4L65E to show up on the small screens. Since that wasn't enough wiring .... I added the BIM-17-2 which adds a compass and outside temperature to the mix (we'll call this DD Box 3). If you're already laughing or shaking your head .....just wait .... the 4L65E also has a main control box to communicate with the above stated electronics. It's made by US Shift and is called the Quick 4. It relays information, allows you to change transmission programming (shift points, etc..), setup 'saved' shift patterns (cruising vrs racing), troubleshoot transmission problems, and probably more crap than I can remember.

By this point you're probably asking me ...."why the hell didn't you just put in a newer style ECU?" or (like my mopar friends) "why the hell didn't you just put in a manual transmission and skip all this $h!t?". Well people...**pause for long sigh** ... it was a very gradual process that snowballed on me. I was like a kid in an ice cream store saying, "i want 2 scoops of this, 2 scoops of that, and ...yeah....mix in some gummy bears and tater tots!"

 

[VitaMeVas]

NOW WHERE THE HELL DO YOU MOUNT ALL THIS CRAP?? (Part 1): I was fortunate enough to install a Vintage Air A/C & Heater setup prior to this. So I had a lot more space under the dash to mount/hide control boxes, etc. Since the DS (left) cowl vent has been removed and blocked off, I had some space to mount the DD Box #1 and #3. I bent up some aluminum to allow me to adjust the compass angle and used threaded crush rivets so I could remove them for servicing.

Then I mounted them where the DS (left) block off plate was. I used 3 of the 4 existing bolts holding the block off plate to mount my brackets. The wiring came later after sorting through the manuals and speaking with Dakota Digital/US Shift Tech Support. I started the wiring loose and tidied up with zip ties as I went. After everything functions correctly, I'll put some wire looms in place. I already rewired the car years ago with an American AutoWire Classic Update Kit. I have no idea how you'd make this all work with an original wiring harness.

 

[VitaMeVas]

NOW WHERE THE HELL DO YOU MOUNT ALL THIS CRAP?? (Part 2):

Just in case I've led anyone to believe that this is all 'plug & play'. This is what my dash looked like for quite awhile.

I found an area on the inside of the firewall where I could use 2 original threaded studs from the original A/C system. I bent up another piece of aluminum, pop riveted more aluminum to it, and installed more threaded rivets for easier removal/servicing of each component. Here's my inner firewall bracket with the Quick 4 and a Bluetooth receiver (for my radio) mounted. Above the Quick 4 is where the GSS will mount. Once again, I used threaded crush rivets on each of the pieces so I could removed them individually later without pulling the whole bracket off.

Here's what this mess looks like mounted to the firewall below the wiper motor. I had enough room to slide half of the bracket behind my Vintage Air A/C main box. I was trying to keep most of this hidden by 'reachable'.

You need to have access to the US Shift Quick 4 in case you need to plug your laptop (PC based) into it's port to do updates. It also has a screen on it's face and a push button that scrolls by turning if you'd like to change from one presaved shift pattern to another (cruise, race, etc..) I mounted them so I could either lift or remove the Vintage Air A/C lower duct tubing to access the Quick 4 if needed without tearing everything apart. The Vintage Air A/C ducting will travel in front of these modules and under the dash so it should hide most everything. It should also give the modules plenty of air movement to prevent overheating. The green toggle switch mounted to the right of the steering column (when activated) gives me the ability to override the automatic shifting of the Quick 4 and be able to manually put the transmission in each gear myself. There's also another black toggle switch mounted under the dash by my right knee for initially programming the Dakota Digital gauges.

 

[VitaMeVas]

NOW WHERE THE HELL DO YOU MOUNT ALL THIS CRAP?? (Part 3):

While I was doing all the module mounting and wiring, GearStar Transmission sent me a few pictures of my completed 4L65E. It was getting ready to be put on their dyno so they could test it and do their break in process. You can see the QuickTime bell housing adapter, but the torque converter wasn't installed yet.

I had to add a kit to my Holley 600 cfm with electric choke to create Throttle Position Sensor (TPS) wiring to send to the electronics. It was Holley kit #534-202. Basically, you're adding a sensor with wires that reads the mechanical turn of the throttle off the carb. In the future, I'm thinking of doing a Holley EFI system. If I do ... the electronic components I've already installed do allow for different EFI setups (including Holley) without tearing everything apart. Here's the side of the carb after the TPS wiring is installed. I hides nicely under the air cleaner when installed.

Here's the DD Box #1 and #3 with wiring mostly done. I'll come back later and tidy it up.

Finally ..... I received a call from GearStar that the tranmission had been shipped to a Fedex Shipping Facility 50 minutes from my place. I don't have a pickup, so I brought it home with a small trailer. For those wondering how long it took to build/ship, I ordered it mid December 2022 and picked it up on February 2, 2023.

 

[Greg Ducato]

Great build, I personally like the integration of modern conveniences and technologies into our cars to make them more enjoyable and enhance the driving experience. Isn't that what hot rodders have been doing since the earliest days of the automobile?
I have used the 4L60E in several of my builds, it is a great trans when built by a knowledgeable builder and fits well in many Mopar applications, I think that you will love it once the install is sorted out and programmed.

 

[VitaMeVas]

Great build, I personally like the integration of modern conveniences and technologies into our cars to make them more enjoyable and enhance the driving experience. Isn't that what hot rodders have been doing since the earliest days of the automobile?
I have used the 4L60E in several of my builds, it is a great trans when built by a knowledgeable builder and fits well in many Mopar applications, I think that you will love it once the install is sorted out and programmed.

Thanks!! Keep posted bc I’m about to have a ton of problems that you can probably answer as I go along. If you’ve done this before, you can point out where everything goes sideways.

 

[Greg Ducato]

I went a little different route on mounting and controls. I use the Wilcap plate adapter system and The Compushift controller.
Which flexplate and crank adapter will you be using? What starter?

 

[VitaMeVas]

Gearstar sent the tranny with the QuickTime bellhousing and QuickTime flexplate. I am using a mini starter from Power Master (XS Torque).

I don’t wanna ruin the thread, but there’s a problem with the above stated parts in my application. Stay tuned.

I went a little different route on mounting and controls. I use the Wilcap plate adapter system and The Compushift controller.
Which flexplate and crank adapter will you be using? What starter?

 

[Powerflite]

I put a 700R4 into my '70 Satellite. It's a great transmission, and it doesn't require a lot of electronics to make it work. I get around 20mpg on the freeway in my wagon with the 318 in there now and it has been working flawlessly for the last 11 years. However, in hindsight, there isn't a huge benefit with this conversion vs. a 727 or 904 with 2.76 highway gears. Off line get up and go is a little better with the overdrive, and mpg is a little better, but overall, maybe not worth the extra trouble. Overdrive is essential with a manual transmission, not so much with an automatic.

Here is a link to the thread I made on it.
700R4 Swap into '66-'70 small block B-body