Replace broken rocker stud

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duanecr

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1973 Mustang coupe with a 302 and 3-speed manual. I rebuilt the engine about a year and installed D00E 351W 1969-74 remanufactured heads from ATK through JEGS (JEGS part #59-2F92). I heard some ticking in the engine and after removing the valve cover discovered one of the studs has broken off at the valve. There is still stud sticking out, but I don't know whether it's press-fit or screw-in. If it's screw-in, I think I can fix it. Press-fit, and I'm not sure I can do it myself. Can anyone tell me which one I have and the best way to replace it depending on which one it is?

Image of head is identification if needed. This was replaced due to the corrosion on the combustion chamber. They shipped one of the heads that way, and I made them replace it.
 

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I'm guessing your rocker studs are 3/8ths, but...... there were also some stepped studs that necked down to 5/16ths at the threadded part. Either way, the studs are a "press fit". You may not have the tool to pull that stud out, but most engine machine shops will have a slide hammer that we use to pull dowels out of blocks, and it can be used for that rocker stud. There is a water jacket below the studs, so you will want to drain a bit of the cooling system before any stud gets removed. A few notes here......Ford used the least amount of "press fit" of all the makes ( Chevy, Pontiac, etc ), and any performance cams/springs will almost always over power the stock press-in studs. Be cautious of your studs pulling up over time.
 
I have been looking at your first photo. It looks like whoever re-built your heads, used what are known as "rail-rocker"rocker arms, with short tipped valves. Maybe it's just the angle from which we are seeing this, but it doesn't look like those valve tip lengths are compatable with rail rockers. Check to see that the guiding lips on the sides of those rockers aren't touching the valve keepers or retainers. Also,..... although those exhaust rotator retainers, and the two-piece retainers on the intakes were used on some factory heads from Ford, they are NOT performance pieces. Those factory pieces are totally adequate for stock useage, but I'm seeing headers and an aluminum manifold, which hints at some performance useage. Just as it is advisable to change out stock Cleveland valves when using a Cleveland for performance use, Windsor Fords ( 260/289/302/351s)should have the studs/rockers/retainers changed for performance use. An exception to the rule is the Hi-Po 289, which comes from the factory with a RPM capable valvetrain. The photo shows a '65 289 head, with a screw-in stud and guideplate conversion, along with original factory one- piece retainers, and short-tipped valves which are used with early rocker arms, used prior to the valve tipped guided rocker arms which started sometime in '66, if I remember correctly. Anyway......just make sure your valve tip length/rocker arm set-up is compatable!
 

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