[GoGoat]

I'm helping a friend install a TH400 in his 65 conv.. He wants to use his 2 speed shifter so it looks correct with console. Anyone been there done this? Or is there another way? The shift rod is too short to reach shift arm on tranny.

[Skip Fix]

Might check Shiftworks they have a lot of kits to modify factory shifters.

[Kenth]

Easy to make an extension of a piece of metal and mount between cable and shift arm.
That´s what i did on my 66 GTO using a TH400 with original shifter.

HTH

[GoGoat]

The 65 did not use a cable. It uses 2 shift rods and a pivot between them. Our probelm is the pivot is in the space the cross member is in. Also the speedo cable wants that space.

[MarkS57]

There's this, not cheap though...

https://www.amesperf.com/parts/62317/

[Goatracer1]

The kit you are referring to is a Shiftworks kit sold by Ames.

[Skip Fix]

Or Shiftworks direct.

[MarkS57]

Originally Posted by Goatracer1

The kit you are referring to is a Shiftworks kit sold by Ames.

I guess so but at a higher cost than Ames. 452 vs 429.

[b-man]

At one time my daily driver was a ‘64 Tempest 2-door coupe that was originally equipped with the standard 215 straight six and the air-cooled ST-300 2-speed automatic.

I transplanted a 455 and TH400 and the column shift linkage hooked directly up to the TH400. I did some minor modifications (filed some slots wider inside) to the steering column to allow more shifter travel so I could manually select low gear, I even extended the shift detent on the column by welding on another piece to extend it.

So the point I’m getting to is the the 2 and 3-speed automatics all have the shift lever on the side of the transmission in the same spot. However as you have already mentioned the shifter pivot welded under the floor takes up the real estate that the TH400 crossmember needs to occupy when you move it back the 6” needed.

You also have a convertible so that presents another issue. You cannot simply relocate the crossmember 6” rearward by drilling some new holes like on a hardtop frame. There are 2 brackets welded to the boxed convertible frame that would need to be cut off and rewelded 6” back.

I ran into the same dilemma on my ‘64 Le Mans convertible. I had a fresh TH400 waiting and then assessed the situation, I ended up selling the TH400 and buying a TH350 to solve the problem.

No need to move the crossmember and no need to remove that shift linkage pivot under the floor. The factory automatic floor shifter and linkage rods will work fine as long as you’re okay with not being able to manually select first gear.

[GoGoat]

Thanks Bman. I'll pass along your info. I don't think he will go to a 350, as he has already had the TH400 rebuilt and tested. I haven't been out to see probelms for myself. I wonder if we can convert shifter to a cable or reengineer rods and pivot.
He added length to the 2 mounts to bolt cross member to.

[Tom Vaught]

I added length to my 64 convertible frame mounts for the cross-member so that the NASH 5 Speed would bolt up properly.

With a Turbo 400 you might have to put a deeper pocket in the trans mount area to get the correct driveshaft angles.

Tom V.

[b-man]

Getting rid of the TH400 solves a lot of issues and saves you money and time.

When I saw the crossmember was going to interfere with the shift linkage pivot mount that made my decision. I was already devising a way to avoid cutting and welding to extend the crossmember mounting brackets but threw in the towel and jettisoned the TH400.

Plenty of strength in a TH350 in stock condition for a stock to moderate street engine. There’s a member here running deep into the 10s with a built TH350 in a second-gen Firebird powered by a 600+ horsepower 455 so it’s more than capable. It gets driven back and forth to the track, it’s a true street warrior.

No driveshaft mods needed either with a TH350, really the smart way to go. If he’s already cut the shift linkage pivot off of the floorboard then it’s all moot at this point.

[MarkS57]

Originally Posted by b-man

Getting rid of the TH400 solves a lot of issues and saves you money and time.

When I saw the crossmember was going to interfere with the shift linkage pivot mount that made my decision. I was already devising a way to avoid cutting and welding to extend the crossmember mounting brackets but threw in the towel and jettisoned the TH400.

Plenty of strength in a TH350 in stock condition for a stock to moderate street engine. There’s a member here running deep into the 10s with a built TH350 in a second-gen Firebird powered by a 600+ horsepower 455 so it’s more than capable. It gets driven back and forth to the track, it’s a true street warrior.

No driveshaft mods needed either with a TH350, really the smart way to go. If he’s already cut the shift linkage pivot off of the floorboard then it’s all moot at this point.

FWIW I did the TH400 conversion on my 65 post coupe. II were to do it again, I definitely would go with the 350. Took me forever to get the driveshaft balance right whereas the 350 would not have required a driveshaft mod. I even think about a 350C lock up because I do highway driving with this beast.

[AG]

I put a TH400 in my '65 hardtop, but like B-man said a 'vert has different problems. I reversed my crossmember and had to drill an additional hole in the frame on each side and get a driveshaft made, it was easy.

[GoGoat]

We got it to work. He is a very skilled machinist, has run his own shop for 40+ years. He also redid the detents in the shifter so would get all positions. Not on the road yet but progressing. Thanks for info. Next is getting drive shaft done.