what all would be needed to change my rearend of my 1976 ford f100 to a dually rearend?

 

Any F350 dually pickup rear up to 97 would fit. Not an F350 cab and chassis dually, only the dually pickup(fender flares)

 

ok because i got my eye on a 1978 f350 with a dually rearend to put on my 76 f100.. sp that would work? There aint no difference in the widths?

 

How do i know if its a dually pickup and not the f350 cab and chasis? anybody got the widths so I don't go accidentally get the wrong rear end?

 

Ford never made a dually pickup until 1980, so a 1978 IS a cab/chassis.
You will need a dually rear end with 3" wide rear leafs, the narrow leafs are always cab/chassis dual wheels. Another way to tell is the rear fuel tank, if it looks flat/wide like your F100 , the rear will fit.

Lots of people put adapters onto 3/4 ton rear ends to fit dual wheels on the back, that would be fine for you ONLY if you aren't going to haul anything in the back.

Cheers

 

get what ever rear you want and move the perchs...

 

Yeah I have a posi dually and springs from a '70's rescue wagon in my '79 F250 Supercab. I only had to move the spring perches and reweld. Took about an hour with grinder and MIG. Rides a little rough empty but works really great towing and the tires last a long time.

 

why don't you just find a good 9 inch?