One of the earlier Ford rocker setups had postive stop studs. The stud was pressed into the head, a specific distance, and the rocker nut is tightened until it tightens on the shoulder on the stud. These were used with cast rail type rockers for rocker guidance. The pressd in stud is not recommended for high performance use, as with stronger valvesprings there is a chance of the stud being pulled out of the head. Comp does make a kit, consisting of spacers under the nut, and special locking nuts, to make this an adjustable setup.
After that Ford switched to the bolt down pedestal type.
The rail type has cast rockers with the litte ears that drop down on each side of the tip of the valve stem, called rails. The pos stop type has these.
They have the rail type rocker. Ford didnt change to the pedestal till 1977. FWIW, comp cams makes a roller tip rail rocker arm. If you plan on using those heads, get the screw in studs. If you have them gone through, they take a valve with a longer stem. If you get ones that are to short, the rails will push down on the spring retainer... not good.
What are the plans? If you put them on a later 5.0, you're probably going to lose power.. pretty sure they have a bigger chamber size than the 302, you'll lose alot of compression...
I was just trying to prove a point to a buddy of mine who tried to tell me they were not rail rockers on that year.
BTW, they would make a little more power on a late model 302 because they have 60cc chambers
Check the crane cams website, www.cranecams.com. They only show pedistal and stud mount rockers as stock replacements. Any shaft mount rocker setups for the Windsor engines were an aftermarket add on.
The 352-360-390-427 FE series engine used shaft mount rockers. The Windsor 221-260-289-302-351 series engines were always stud or pedistal mount rockers from the factory.
I think you are mistaking shaft mount rockers and rail type rockers as being the same thing, they are not.
Rail type rocker arms, as have already been said, have little ears that help keep the rocker tip center on the tip of the valve stem. If you look at the following picture, you can see the little ears sticking down past the roller tip. http://static.summitracing.com/global/images/prod/large/cca-1450-16_w.jpg
I'm sure you know what shaft mounted rockers look like, so I won't waste your time by posting a picture of them. But, Ford started using the rail type rocker arm in 1966 and used them for quite some time until the introduction of bolt down pedestal type rockers much later.
I think you are mistaking shaft mount rockers and rail type rockers as being the same thing, they are not.
Rail type rocker arms, as have already been said, have little ears that help keep the rocker tip center on the tip of the valve stem. If you look at the following picture, you can see the little ears sticking down past the roller tip. http://static.summitracing.com/global/images/prod/large/cca-1450-16_w.jpg
I'm sure you know what shaft mounted rockers look like, so I won't waste your time by posting a picture of them. But, Ford started using the rail type rocker arm in 1966 and used them for quite some time until the introduction of bolt down pedestal type rockers much later.
I see what you mean now. I knew that the early Windsor engines used a ball type pivot for the rockers, like the SB chevy engines.I didn't give much thought as to how they kept them lined up over the valve stem.