I was under my 1980 f150 today cleaning it up and getting it ready to put my 351C in. The truck originally had a 351M in it. After I was done pressure washing the twenty plus years of grease and dirt out from under it i happend to look at the rear diff tag and it said the gears were 2.75. thought that could'nt be then proceeded to find that tag was right, it was 2.75. I'm thinking that this may not be thr original rear end in the truck now. I always thought that all the 80 - 96 f150 4x4's came stock with 3.50's. There was no tag on the dana 44 IFS in the front for me to compare it too. I'm hoping the on ly thing I gotta do is swap ther rear diff. I would appreciate the info fellas.

IF YA AIN'T EVER BEEN STUCK, YA AIN'T BEEN 4WHEELING

 

I have a 83 f100 that had a 300 six originally. It has a 3.50 rear end. FYI...Dave

 

You have to swap both if you got 4wheel drive and My dad had an 80 150 with a 3 speed on the tree it had a 2.75 9" nodular rear w/posi I still have that rear thought it might come in handy somewhere. John

 

so i'm taking it that there is a possibility of ther front also having 2.75's........ the truck originally had a 351M and a C6

 

Have you ever used the 4wheel drive? if so you would know if the rears are mismatched. it is very possible that the truck came thru with this gear ratio. John

 

nope never used the 4 wheel drive....... i got the truck in pieces.

 

John,
i purchased the truck with no motor and 7" of lift, 3" body and 4" suspension. when i got it the tire were a stock size and I went ahead and slapped a set of 35's I got for a $100. with that gear ratio I'm gonna be lugging down the motor. I've never heard of a 2.75 stock gear in a 4 wheel drive. thats why i was hoping the last owner " A REAL GENIOUS" from what i've been told might have just swapped the rearend with out knowing

 

I have a 1980 4x4 xlt ranger originally with a 302/c6 and it has
3.50L in the rear and I think it's a 3.55L dana 44 in the front.

 

The front diff. should be one or two points off of what the back is ie. 3.73 rear 3.70 front I guess you'll have to do the spin test mark the rotors and then turn them and count how many times the drive shaft spins. John

 

Hey,
My 83 f 150 xl and most dana 44 ifs's came with 3.54's.i wouldn't imagine the truck being very streetable or usable with the lift and tire size you mentioned and 2.75's . are you sure you're reading the tag right?I dont think i ever heard of a stock geatr ratio that high.Good luck.

Jon

 

i finally got the time to check the front diff. It's a 3.54 and the rear is a 2.75. now what i need is a rear3.50 diff. I also pulled the t- case apart and there is no damage. I guess the last guy never used the 4 wheel drive after he swapped the rear end. thanks fellas for the inputs....

 

Hey, I just thought of something, I bet you could outrun fordsajoke with that rear in there!!!!! LOL JOHN