i have a 77 460 im putting in a 77 f-100 for a show/drag truck. im using original heads and im just gasket matching the intake/exhaust etc. anyway i am running new comp cam roller rockers and i want to put in a 7/16 rocker arm stud. now the previous rocker stud is allready taped for a 5/16 and it has two lips on top of the guide. now my q is how far must i take the surface down to keep my geometery the same and not have to switch pushrod lengths. how would i go about measuring it or is there a set deminision allready. please and thank u. i would appreciate answers soon cause the motor is allready in the shop now. and go figure the guy doing it has never done a head with it allready tapped so he doesnt want to take a chance in messing it up

 

If he has no experience machining the heads now is not the time for him to learn on your heads. These are compound angles and you have to know what your doing. If you are just going to run a hydro cam then why not just get a conversion kit and avoid all of this work ? They use the 5/16 hole thats already there and will handle 350 pounds of spring psi load with no problem. You will need to check for push rod length, I doubt the stock length would be right.

 

You have the d3ve heads. They are a 93cc chamber and can make good power if worked over properly. To fix your rocker stud issue, there are several ways to go. 1st is to machine the pedistal and drill/re-tap the hole for the 7/16 studs. 2nd is to contact Randy Malik at www.rmcompetition.com as he has rockers that will let you keep your studs and not have to change anything else. Or lastly, you can search out the Crane stud conversion kit that will get you the converstion stud as well as a guide plate so you can run off the shelf roller rockers.

 

i dont beleive i have the dove heads. but anyway i want to drill and retap the hole for a 7/16 but i have to know how far to mill the pedistol down so it sits right and doesnt mess up the gemotery of the valve train.its allready taped for a 5/16 there is two tabs on left and right side of pedistol that are extruded and i just need to know what to do in order to machine that pedistol down so that the geometry doesnt change

 

I didn't say d0ve, I saod the more common lower compression d3ve head. Do a google search on d3ve rocker stud conversion if you are set on drilling, machining, and re-tapping the stud bosses. It's a rather detailed process where you need to machine to certain specs for it to be right.

Also, on the side of the head will be a casting number that will tell you what heads you have