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I finally found some time to crawl around underneath my '68 F250 4x4 and scrape enough grease and dirt to find the code plates...here they are. Any help in deciphering them is creatly appreciated!
Transmission and transfer case gear ratios?
BTW: I am entertaining the thought of swapping out the front and rear r&p gears for something a little more "highway friendly"...any thoughts?
front axle:
4 . 09 D3TA-GA
603395-1
rear axle:
4 . 10 D3TA-MA
603382-11
tranmission:
D3TA7003DC FL112
6 1 73 435
transfer case (New Process):
MODEL: 205
RATIO: 196
SERIAL: 8 31 73
ASSEM NO: D3TA7A195AA
Well, this is interesting. You state that your truck is a 68 model yet every code you gave was for a 73 model! D3TA means 1973 truck assembly.
The 603395-1 and 603382-11 numbers for the diff's are called "Bill of materials" numbers. It looks like you have a 4.09:1 ratio Dana 44 front and a 4.10:1 Dana 60 rear.
Your tranny is a New Process 435 4-speed that was born on June 1, 1973. The ratios are: 1st 6.67:1, 2nd 3.32:1, 3rd 1.74:1, 4th 1:1, reverse 8.258:1
Interesting...I know the VIN doesn't match my truck (it says my truck is a 2wd F100) which leads me to believe that the driver's door has been replaced.
Any thoughts on why the entire 4wd drive train would be swapped out from a '73?
Was the 4.10 rear / 4.09 front axle combo standard on the older F250's?
Any thoughts on more "highway friendly" axle ratios?
There's no telling why the parts were swapped. Someone may have put a 68 body on a 73 rolling chassis.
There is suppose to be a VIN stamped into the frame rail. You could try and find it and compare it to the door. Sometimes they are hard to find. It is usually on the passenger side rail, stamped into the top, about where the firewall is, give or take a foot. You will need a small mirror.
Those axles/ratios are very common for this era F250 4x4. They were never designed to be highway friendly. I reckon you could change the ratio to something in the 3.5 range but it won't be cheap. It's better to have a little rice burner for the highway.
"It's better to have a little rice burner for the highway."
AGREED!
It is looking more and more like I have a "mutt" on my hands. No worries as the truck is in great condition...just curious. I hope to have the cab off the rails sometime in the fall when my new house (and garage) is done.
A friend has a '79 F150 4x4 parked on the side of his house (t-boned last fall at the driver's door) and I am thinking about taking the axles off his hands. I know it would change the load rating for my truck, but I don't do any heavy hauling anyway. Just a thought.
Thanks again.
-Craig
The NP205 is a bulletproof t-case and as far as your axles the 44 is a good axle and the only reasonable swap is a high pinon 60 with disk brakes or a 44 with disks if yours dosen't have them. The rearend in your buddies f150 will have different mounting positions for shocks and springs and be a pain in the butt for no big gains and the front axle would be a light duty 44 most likely. What size tires do u plan to run? depending on that and the fact that you want highway mileage make your choice on a gear ratio. I run 35's with 4.10's and a 460 with no problems hittin over 100mph or eating up the imports off the line.
Hi, I reckon you could change the ratio to something in the 3.5 range but it won't be cheap. It's better to have a little rice burner for the highway.
Lee
Lee, It is never ever good to recomend a rice burner on the worlds largest and best Ford truck site. A little 4 banger Ranger, or Escort or something but not a rice burner. That is almost like a death wish, kinda.