screw in studs on stock heads

[5.0tbirdguy]

I found a $40.00 screw in stud kit on ebay with guideplates and pushrods.

Is it REALLY neccesary to mill the pedestal boss or could I just drill and tap the holes and be done?

 

[352Ford2]

what are the year and casting number of your heads, this all depends on that.

 

[5.0tbirdguy]

They are '99 model gt40-p heads.

The only reasons I can think of why they wouldn't work without milling .230" from the boss are- stud hitting the valve cover, the rocker hitting the guideplate or the guideplate not lining up correctly. Would any of these be an issue? Has someone done this before with no problems?

 

[retro50]

If you don't mill the bosses you will probably run out of threads before the rocker is even adjusted properly.

 

[352Ford2]

why are you trying to put studs and guideplates on a pedistal mounted head? what are you trying to gain?

the reason this conversion became popular is to convert the later (68-late 70's) rail heads to the early stud mounted heads

 

[EMW150]

Crane sells coversion kits for what you're trying to do. Go to summit and search this# CRN-52655-16. It says no machine work required.

 

[jackchan]

i had it done to a pair of E7's about 6 years ago. The guys shop is in my sig that did the job. He knows all those answers. Strength is the main reason you would want to do it....He used ARP on mine. give him a call his name is Jerry Chambers at the HEAD Shop. Or thumper 460 also does this from here on the board. Hes located in Florida. Either one can answer your questions
Jack

 

[352Ford2]

They are only mildly stronger than your fadtory set up, and the thing is you don't need a fancy valve train when running gt-40's cause its not like you are going to be making power up high. Save your money for some roller rockers.
(I am assuming you are not running a mechanical cam)

 

[jackchan]

the factory studs are press in fit, they can pull out with moderately stonge valve springs, larger cams with any kind of rpms.........I'd do screw in's with larger studs.........
Jack

 

[352Ford2]

unless I am retarted, pedistal mounted heads are NOT pressed in, they are held down with 5/16 bolts.

you are thinking old the older heads

 

[jackchan]

lol I stand corrected! it is I that is retarded! I guess what I meant was that you should upgrade to the larger studs (screw in when you can)

 

[5.0tbirdguy]

I'm going to use Scorpion roller rockers, but with pedestals it might be a pain adjusting the preload.

The cam is a Comp xe266 with .544/.555 lift. I'm sure it will have a reduced base with that lift. It might even have two different base circles the way they make cams these days. In 10,000 miles I'd rather adjust the rockers than add a shim when everything seats in.

 

[rd]

The reason you mill the pedestals is so that you have room to adjust the rockers, so the rockers dont hit the studs, and so there is room for guideplates.

I have done it both ways. Currently, I am using Comp Cams retro stud kit, with 5/16 thread to fit the pedestals and 7/16 for the rocker adjustment. I used roller tip rail style rockers so I did not need guideplates.

You either need to look at a similar combo or mock yours up. You can always take it apart to mill if it does not work.

 

[troyGT03]

machine work to make room for guide plates and studs. no other option. otherwise wont work except than the retrofit that rd said. done it both ways also for customers.