Does anyone know?

Does anyone know how much you need to machine off of the stud bosses on a sbc to use screw in studs and push rod guide plates?


Thanks

 

Thickness of the guide plate if I remember right

 

I take 1/2 inch.
Jeff

 

I thought there was a readily available tool to do this........

 

Yes , there is a tool. You still need to measure the thickness of the guide plate and the shoulder of the stud. That is how much to remove from the boss. The diamensions vary from mfg. to mfg. .. Also best to start by removing one stud from the center of the head, cut the boss and trial fit a plate and stud.. compare height with the other 7.. adjust your tool accordingly...
Good luck
Dave

 

It's specifically for that reason I took my heads to a machine shop. I don't know how much they removed, but it was a pretty good whack.
It's got to be PERFECTLY square. Then, you'll need to drill out the boss a little bit with the proper sized drill bit to work with the required tap. And that, too, has to be PERFECTLY square.
Wasn't worth me trying to do it on my Craftsman drill press and screwing up a set of heads, when the local machine shop does this process every weak.
I did elongate the pushrods holes myself with the tool from Comp.
I also just remembered that the factory pressed-in studs were absolute mothers to get out. There's a special tool to do that as well...I tried it myself, and no go. The ones in my heads must have been extra special though, because the machine shop broke two of them off, and busted the special tool too.

I set about thinking I could do it myself as well. The magazines always make it seem like you can, and COMP sells the tools, but there was no way in hell I could do it, and do it right. Not without a bridgeport.
And I'm fresh out of bridgeports.
-Brad

 

Most machine shops will use a guide & seat machine. If you are using stock length studs measure the length from the shoulder to the end of the stud, then add the thickness of the guide plate. Then measure a few studs before you pull them. You cut the difference which will be about 1/2 inch. You level the head up in the machine. After I get it set up I always ran a 3/8 drill through the holes, otherwise they tap really hard. The hole is a few thousands under 3/8. I always started the tap in all the holes to so you keep the threads straight. Best to have it done if you don't have the equipment.
Jeff