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It appears the PO installed roller rockers on a non roller motor 1972 302. The result, arms wiggle from side to side and one walked off the valve stem...no damage. The questions is, a friend said to install a guide plates which means removing the heads and rebuilding. These heads (72) came with rockers with rails to keep them centered, can't I use those? Musch easier on the install.
 

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NO I don't think you have to remove the heads to install guide plates.. The guide plates are held on with the stud that holds the rockers on.. At least thats how it is on my 460. I added roller tip rockers with the guide plates and poly locks and the guide plates attached under the rocker stud.
tim
 

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Yes you can get some "rail" style roller rockers. There more pricy i think than regular rollers. The roller actually has a Lip on either side to keep it from falling off.
Do some calling around to find them, Crane Cams, Comp cams.Etc. Summit racing.
Good luck
 

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On 2006-11-14 06:50, pedal2themetal45 wrote:
NO I don't think you have to remove the heads to install guide plates.. The guide plates are held on with the stud that holds the rockers on.. At least thats how it is on my 460. I added roller tip rockers with the guide plates and poly locks and the guide plates attached under the rocker stud.
tim
That is not normal for most heads. Most use press in studs. Most heads have to be machined/tapped to accept guide plates and studs. 289HP heads, BOss 302 and Boss 351C and a select set of big block heads came from the factory with studs and plates. The rest did not.
 

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can get roller tip rail type rockers (ball pivot centers) from either comp cans or crane, i forget which. spring pressure must be under 350 lbs open to use them.

technically you need to take about 1/4" off the stud bosses to install plates and screw in studs. easier to take heads off to mill and tap for them, but i have heard of it being done on the car. makes a mess of chips, tho.
 

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OK My mistake I was thinking of my 460 Iron D3 heads It had those rockers that were held in with the U shaped things that held intake and exhagust rockers on... not shafts..... I got a guide plate kit from Cran I beleve that had screw in studs that screwed into the 3/8 hole and up the size to 7/16 I beleve and the guide plates were noticed to fit over the bossing under the rockers so no machining was needed. the new studs held the guide plates on.
Tim
 

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If you changed the springs to anything other then stock, or the lift of the cam changed to anything other then stock....

Screw in studs are required no mater what type rocker you can get..... The increased pressure on the studs will pull them right out of the head.

If you are not doing any valvetrain , cam changes then you should just use new stock replacement rail type rockers.

Something is wrong if you have a roller rockers in that block... what else is not stock....? You may have more issues then you can guess at, and right now is the right time to find all the issues....
 

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Early 429 and 460 heads had screw-in studs from the factory. They came with shouldered, positive stop studs where the rocker was simply 'tightened all the way', but they were indeed screw-in studs. The studs need swapped out for the standard type if an adjustable valvetrain is desired, though.

Do NOT attempt to set a head up for screw-in studs with the head still on the engine! The stud boss needs milled down the height of the hex nut on the stud, AND THE HOLES NEED TAPPED ABSOLUTELY STRAIGHT!!!!!!!

Just running a tap down the hole will leave the rocker studs pointing in all different directions. Don't ask me how I know this!!!! I JUNKED the first set of heads I ever ported by trying to do that! It's pretty dis-heartening to be all proud of your work, and then see the studs pointing in all directions after they are screwed in! NOT GOOD! This needs done on a machine that will tap the holes ABSOLUTELY PERPINDICULAR WITH THE HEAD. Do not try this at home unless you've got a way to do it right.

And yes, screw-in studs are needed with aftermarket camshafts and their required springs. You -can- pin the stock press-in studs, but if the stud breaks, you're screwed.

Good Luck!
 

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Get some shaft mount roller rockers of ebay. think the got for $250
I love mine.
 

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This needs done on a machine that will tap the holes ABSOLUTELY PERPINDICULAR WITH THE HEAD. Do not try this at home unless you've got a way to do it right.
Not all heads follow this rule, if in doubt, machine the rocker post perpindicular with the machined top of the stock post.
 

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Because the studs have a hex head on them and the guide plates are .1" thick you have to mill .3" (according to Ford and the machinist that did mine) off the boss then you drill and tap 7/16" NC at 90 degrees to the head surface. You put the guide plates on and thread sealant on the studs and install and torque them to specs. You can only use rail rockers if the rebuilder installed the taller valves. If the rebuilder put in the shorter valves you are going to have to use guide plates and hardened pushrods. The way to tell is to look at the part of the valve that sticks above the retainer. If it is less than the diameter of the valve stem high then you can't use rail rockers - if it sticks up above the retainer more than the diameter of the stem then you can use rail rockers as long as you are using a hydraulic cam. Ford recommends that for solid lifter cams you use the non-rail rockers. You should also keep in mind that if you are using a cam with more than .5" lift, the slot in stock rockers will have to be opened up to ensure that you don't bend studs.
Paul
 

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Yea frdnut
thats what I'm using on my 460 with there guide plate kit. they work real good so far.. 3yrs..no prob. I did have to use the Mr. Gasket Poly-locks as the other types had a little shoulder on the nut that was hitting the rockers and makeing them bind up. there wasn't enough clearance inside.
tim
 
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