• When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.

Rearend Gear

70plygtx

70plygtx

Member
Local time
5:09 PM
Joined
Jun 28, 2011
Messages
19
Reaction score
11
Location
Indiana
anyone know what the standard rearend gear for a 1970 440 GTX was factory? Had this car for 8 years and yesterday was the first time I drove it more than a couple miles. It has 4.10 gears and is clearly way too much. Which I knew it would be. What the car has when I bought it. Just looking at possibly changing in the future.
 
Dana or 8 3/4? Stick or auto? If a dana, 3.54 sure grip standard, 4.10 optional.
Hemi, 440-6, 440-4?
 
If you want to change it what difference does it make? If the engine likes it do it.
 
What size radiator do you have? 22" or 26" Do you have A/C?
If you have a 26" radiator and no A/C you car could have been equipped with a axle package.

Mine has a 4.10 rear, but the car was originally with a 22" radiator and a PO made a 26" fit.
They did never change the speedometer gear in the transmission which was a teeth count for a 3.23.
Guess also the 3.23 was standard for 440's.

My future plan is also change it, either a 3.23 or a 3.55.
 
From the 1970 sales brochure:
upload_2019-7-6_1-6-12.png
 
An actual GTX only had the 440, 440-6 & Hemi as engines and had the performance axle package 8 3/4- 3.55 or 4.10 Dana 3.54 or 4.10. IIRC 4 spd's all had Dana's either 3.54 or 4.10. 727's could have either 8 3/4 or Dana & either gear ratio.
 
Did ANY automatics get Dana? Post 6 says no for 70.
 
Dennis H said:
Did ANY automatics get Dana? Post 6 says no for 70.
Click to expand...

In the list it doesn't state anything about Dana's, maybe they were available for both but not mentioned for manual as well as automatic?
 
Dennis H said:
Did ANY automatics get Dana? Post 6 says no for 70.
Click to expand...
the 4.10 option on the last line is a Dana. In 1969 Chrysler found that the 3.91 8.75 wasn't strong enough. In fact, broken 3.91 rears coming in for warranty work had Dana 4.10 replacements installed. Oddly enough, the paper mentions ROAD RUNNER AND G.T.X. EQUIPPED WITH 383 C.I.D. 4-BBL. ENGINE AND 4-SPEED MANUAL TRANSMISSION, something that wasn't in a GTX.
upload_2019-7-6_11-31-22.png
 
The sales brochure in #6 is for ALL Plymouth models. No slant 6's in GTX's. Road Runners standard was 383 "Magnum", optional were 440-4, 440-6 & 426 Hemi. Standard for GTX's was a 440-4, 440-6 & optional 426 Hemi. Dana's were certainly available behind 727's as well as 4 spd's in 1970. Track Pak axle package had the 3.54, Super Track Pak had 4.10.
 
You must log in or register to reply here.

Similar threads

B
8 3/4 Rearend Setup Subject Matter Expert Question
Replies
17
Views
833
Don Frelier
Don Frelier
Hubert
A833 4 speed question
Replies
5
Views
882
Hubert
Hubert
S
A-833 overdrive options-
Replies
16
Views
2K
AJReigart
AJReigart
fourgearsavoy
Gear quality and getting a good set-up
2
Replies
29
Views
2K
fourgearsavoy
fourgearsavoy
chevyguylost
Dana 60
2
Replies
34
Views
2K
Cranky
Cranky
Auto Transport Service
Back
Top