Hey I have a 1970 F100, 302 3 speed. Can anyone tell me what the rear end ratio is if it has Axle Code 08? My parts truck has axle code 09 Can anyone help me with that?

I tyyed the search already but nothing, your help would be greatly appriciated!!

Scott.

Speed Kills, play it safe drive a chevy!! LOL

 

According to the Chilton's manual:
08 = 3.50, from '69 thru '77
09 = 3.70, from '69 thru '77

You will get a little better take off, but your top end will suffer a little. You will also need to change your speedo gear at the tranny.

----Patrick

 

Hey I was wondering if anyone could give me conformation, I could have sworn i was running a 308 rearend, at least thats what I thought cause I cannot break the rear tires loose without a whole lot of rpm, and this truck is rated at 210 hp. Not Like I have big tires or anything either, just a set of 225's thanks for the info

Does the rearend have any casted numbers on it? The rearend might have been switched

Any idea how much mileage/horsepower i would have lost by having the spark advance vacuum hoses backwards?
The timing was retarded by about 15 degrees when it should have been advanced about 20-25 degrees. OOPs (the hoses were like that when I bought it, i think the intent was to by-pass pollution controls)

 

Well, the best way to figure out what you have is to pull the carrier and count the teeth on the ring and pinion.
Example: 41 teeth on ring gear divided by 10 teeth on pinion; 41÷10= 4.10.

The quick way (also known as "Close enough") is to jack up the rear of your truck and put the truck in neutral, be sure to use jack stands and chock your front wheels. Then with a some chalk, grease pencil, or even paint, make a mark on your driveshaft and on your tire.
Rotate your driveshaft and count how many times it rotates compared to ONE full rotation of your tire.
If the driveshaft rotates just over 3 times to one tire revolution, then you are probably right around a 3.08.
If the driveshaft rotates 3 1/2 times...then 3.50.
If it rotates close to 3 3/4 times...then 3.70.
And so on and so forth......

As far as the vacuum hoses go....can't help you there, BUT you should be able to break those rear tires loose now.

I hope this helps a little

----Patrick

 

Thanks for the replies, much appriciated!