Hot Rods F-1 F100 Steering boxes

How can you tell them apart??? I want to purchase the AV8 headers for my project from Red's but I can't remember if my steering box is F1 or F100.

 

The F-1 has a splined and threaded end on the sector with a big nut holding the pitman arm on. The F-100 has a mostly smooth sector with just a few splines, and a pinch bolt holding the pitman on.

The worm shaft of the F-1 is below the sector. The worm shaft of the F-100 is above the sector.

 

Alchemy is right about the location of the shafts. At first I used a F100 steering box in my 33 Ford coupe, but the shaft was too close to the exhaust manifold on the 53 Cadillac 331 engine. So I redrilled the frame holes and installed a F1 box - plenty of clearance now. The lower shaft on the F1 made the difference.

 

Left to right , 48-52 F1,, 53-56 F100,, 57-63 F100

 

Thanks guys...I have an F1

 

Thanks for that picture and descriptions. I recently went to a guy's house from work where his elderly father was cleaning out all his old truck parts from his shed. He had so many parts from different trucks he had owned he wasn't sure which trucks they were from.