Modifying early tranny cover to work with a 4 speed tranny - need a measurement

[Steve Abbott]

I'm in the process of modifying an early transmission cover to work with a 4 speed tranny. Can someone tell me how far the top of the shift tower sits above the top of the tranny cover? My drivetrain is out of a '78 if that matters. Thanks in advance!

 

[Living in the Past]

My loose transmission covers are in another location. Found a couple of pictures that mine help. This a picture I found that I posted sixteen years ago. Shows the four speed cover on top of a pre 9/72 cover. The 9/72+ three speed cover is the same hight as the four speed.

Few years ago I was comparing my 3/73 FST with a three speed to a 78 cover I had. This shows the height with a four.

 

[Steve Abbott]

My loose transmission covers are in another location. Found a couple of pictures that mine help. This a picture I found that I posted sixteen years ago. Shows the four speed cover on top of a pre 9/72 cover. The 9/72+ three speed cover is the same hight as the four speed.
View attachment 3727087View attachment 3727088
Few years ago I was comparing my 3/73 FST with a three speed to a 78 cover I had. This shows the height with a four.
View attachment 3727089

Thanks for that pic. I'll measure my early cover and see what the difference is between that one and the 4 speed. Thanks!!

 

[EWheeler]

Hope these help:

 

[Its me shaneus]

Heres an example of how not to do it! I added 1 1/2” to clear an H55 trans. Less mona lisa, and more frankenstein!

This is my 1970 40 with a later model heater box and a later model tunnel cover with the tail end cut off and a lift kit added. Needed to lift the heater box to clear what I had made and I liked the newer style box better.

 

[Living in the Past]

Heres an example of how not to do it! I added 1 1/2” to clear an H55 trans. Less mona lisa, and more frankenstein!

This is my 1970 40 with a later model heater box and a later model tunnel cover with the tail end cut off and a lift kit added. Needed to lift the heater box to clear what I had made and I liked the newer style box better.

View attachment 3727610

Going to H55F on a pre 9/72 tub is a lot more difficult than a H42. If you have an 10/82+ FJ40 with a four speed the five speed would be all bolt in parts.

The heater no matter if from the pre 74 or the 74+ will work with a H55F. The 10/82 transmission tunnel which is part of the tub only raised just Infront of the inspection cover. The driver's side was the same height as the pre 10/82. It raises shortly after that. The tunnel itself flare up after it clears the heater. This would require a lot more metal work on previous years. The 10/82+ 40 series the H55F will only clear the inspection cover with the 40 series H55F covers. This transmission hump and inspection cover was on all 10/82+ 40 series. The 60/70 series top cover besides not fitting requires a more vertical shift cane which changes the whole feel of how the transmission shifts. The H55F doesn't shift as smooth as the H41 and H42. Being more vertical makes it worse.
Here are 1/79-9/82 inspection covers compared to the 10/82+ inspection covers.

 

[65swb45]

Take @EWheeler measurement and subtract the height of the bolts that hold the shift tower to the top plate, and that’s how much sticks out.

I literally had the bolts shaving the paint off the underside of my trans hump when I did the 4speed swap..

 

[Steve Abbott]

Take @EWheeler measurement and subtract the height of the bolts that hold the shift tower to the top plate, and that’s how much sticks out.

I literally had the bolts shaving the paint off the underside of my trans hump when I did the 4speed swap..

Per the pic posted above by @Living in the Past, the 4 speed tranny cover was 6" tall and my early 3 speed cover is 5" tall, so I'm thinking I would need to add around an inch in height. As it is now, there is no way to bolt the early cover on since I'm at least 1/4" away from the floor on the front half of the cover with the cover sitting on top of the tranny.

 

[Living in the Past]

Per the pic posted above by @Living in the Past, the 4 speed tranny cover was 6" tall and my early 3 speed cover is 5" tall, so I'm thinking I would need to add around an inch in height. As it is now, there is no way to bolt the early cover on since I'm at least 1/4" away from the floor on the front half of the cover with the cover sitting on top of the tranny.

I know some have managed to use the pre 9/72 tunnel cover. Found it easier to just trim the back of the 78 tunnel cover. I am thinking of using the passenger section from the original three speed cover along the floor grafted in the 78 cover. The area for the vacuum shifter is the only place the floor or bolts didn't line up.