5 speed/6 speed

ord27 · Jan 10, 2022

What do you guy s think?
1970 Superbee used for a highway thumping road trip car

5 or 6 speed?
I don't want to cut the tunnel. The paint and body work is already done.

go with Silver sport or American Powertrain?

thanks

Darter6 · Jan 10, 2022

ord27 said:
Silver sport or American Powertrain?

I kinda think they sell the same equipment. I did a Keisler 5 speed swap (Keisler sold out to Silver Sport) in my 65 and long hauled 2 Hot Rod Power Tours with it.
Also did the same with a Duster. Rear gear was 3.55 in the Duster and it had too much cam and didn't like 5th under 65 mph. The 65 we ran 3.73 and it was a happy car. Cams were real close in specs. Do you need a 6 speed ? Totally up to you.My 2 cents.

Chi Town Runner · Jan 10, 2022

ord27 said:
What do you guy s think?
1970 Superbee used for a highway thumping road trip car

5 or 6 speed?
I don't want to cut the tunnel. The paint and body work is already done.

go with Silver sport or American Powertrain?

thanks

I haven't checked in awhile but even with the Silver Sport 5 speed TKX you will have to cut the tunnel to accommodate the shift lever position. They give you a template and a pre-cut metal piece to place over the hole that you cut in the tunnel.
That was the only reason I haven't made the switch. If you find out otherwise please let us know.
Good luck with your project and keep us posted.
Frank

Kern Dog · Jan 10, 2022

As stated, the decision to step up to the 6 speed is really predicated on whether your engine has a bigger than stock type cam. A cam that is too big will be inefficient at low cruising rpms where the .50 6th gear operates. Obviously, the 6 speed is a physically larger transmission so more cutting is needed to fit. I chose the TKO 600 5 speed. I have a thread on the install and all the little obstacles I encountered along the way.
I think the title was “Tremec 5 speed in a 1970 Charger “.
Good luck.

CoronetDarter · Jan 10, 2022

I've dealt with SST on a couple of issues I had with my Keisler Engineering Tremec. Great customer service. I've never dealt with American Powertrain.
The Dart has a 5 spd behind a built 360 and with 3.55s it dogged in 5th below 2,000 rpm. Swapped in a 4.10 gear and now we're talking!

Cojohnso1 · Jan 10, 2022

The only direct bolt in 5-speed replacement transmission is the A855 Passon. Where 5th gear is .70.

Availability and now some quality concerns are the top issues. Certainly Availability.

Chi Town Runner · Jan 10, 2022

Cojohnso1 said:
The only direct bolt in 5-speed replacement transmission is the A855 Passon. Where 5th gear is .70.

Availability and now some quality concerns are the top issues. Certainly Availability.

Oh yes.
Just look at "Moparts" blog. AVAILABILTY is a major issue

Darter6 · Jan 10, 2022

I just wanted to add that we did a Passon 833 conversion 4 speed OD in a big block 73 Cuda that was great.
It too was a long haul Hot Rod Power Tour car. 451 4 speed OD 3.73 gears. Dang thing got 18-20 mpg.
Car was no A/C manual steering no power anything ride.

BMosely · Jan 10, 2022

I just did the TKX in a B body. The picture below would be the only hole required. I was originally getting a TKO so I had already cut the larger opening. The TKX fits tight without mods. One spot in the drivers tunnel will need a “universal wrench” tap for a small horn corner of the TKX.

ord27 · Jan 11, 2022

thanks for the responses. Yea, I will go with the 5 speed. I was under the impression that no cutting was needed with the 5...oh well, no biggie

joe smith · Jan 15, 2022

BMosely said:
I just did the TKX in a B body. The picture below would be the only hole required. I was originally getting a TKO so I had already cut the larger opening. The TKX fits tight without mods. One spot in the drivers tunnel will need a “universal wrench” tap for a small horn corner of the TKX.

View attachment 1221904

The TKO is no longer being manufactured by Tremec, it has been replaced with the TKX...
TKX is a bolt in on my mustang.... ...

5 speed/6 speed

ord27

Well-Known Member

Darter6

Well-Known Member

Chi Town Runner

FBBO Gold Member

Kern Dog

Life is full of turns. Build your car to handle.

CoronetDarter

FBBO Gold Member

Cojohnso1

Well-Known Member

Chi Town Runner

FBBO Gold Member

Darter6

Well-Known Member

BMosely

Well-Known Member

ord27

Well-Known Member

joe smith

Well-Known Member

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