Rocker arm stud replacement

[rfoll]

I have a set of stock 305 heads I was going to use and noticed one of the studs was chewed about 1/3 through. I haven't replace one of these since 1976 when I popped one out of the head on my L76 327. I have no idea what I did back then and have gotten wise enough< (as in old enough), to think there is a standard procedure for this. Suggestions are very welcome. Thanks, Rick.

[Dave Koehler]

Pressed in studs. A proper tool makes short work of it.
No tool?
Stack up washers or rocker balls and get the impact out.
Pull until you run out of thread.
Remove nut and add washers.
rinse and repeat

[rfoll]

Will a used stud from a junk head be ok if I lokctite it in? I guess my question was more about installation. This will be a stock application.

[dannobee]

Summit and others sell the little guide block tool to do this job. If you don't have access to a machine shop, use it. Otherwise the studs will point at all kinds of different angles and will look like a big block head when you sight down the studs.

[Dave Koehler]

Summit and others sell the little guide block tool to do this job. If you don't have access to a machine shop, use it. Otherwise the studs will point at all kinds of different angles and will look like a big block head when you sight down the studs.

He is not doing a screw in stud. Simply replacing a stock pressed in stud. No biggie. Just muscle.

[Dave Koehler]

Will a used stud from a junk head be ok if I lokctite it in? I guess my question was more about installation. This will be a stock application.

That can work. I would not use the loctite. It may set up before you get it all the way end. Those have a pretty good press fit on them.
If you have access to a lathe you can machine a round chunk the depth you need to pound it in.
Measure the height and machine the hole the same depth.

[engineguyBill]

I would recommend that you take the head to a machine shop for stud replacement. SBC rocker arm studs are available .003" oversize diameter and the stud hole in the head must be reamed .003" oversize prior to installation. At the machine shop the stud will be installed while the head is set up in a vertical mill to insure that the stud is absolutely straight. If you install the stud be just hammering in a new one, the chances are pretty good that the stud will be out of kilter and it only takes a thousandths or two for the rocker arm to eat up the stud again (or worse).

[F-BIRD'88]

When you are done replacing that rocker stud drill and roll pin them all

[Dave Koehler]

Bill,
Not trying to create a rift here but not every stud hole needs to be oversized.
IF he is not machining the hole where is the concern that it is going to be off kilter and he needs it done in a shop?
I did far too many of those R&R jobs in the 70s and just don't see why he needs a shop for this one off R&R.
Heck, unless the shop is run by an OG chances are the new kids don't know what to do with it anyway.

[MotionMachine]

Just add to the mix, the old RM348 Pioneer is 7/16 thread and the head is already close enough to that tap drill size. Surely by hand one can easily tap it straight.

[Lizardracing]

Some of you guys are working really hard this lol It's a SBC, not a Swiss watch.
Stock ones weren't all that straight or at the same height to start with as the factories and manufactures knew what was close enough to get past the bean counters and warranty periods.

The easiest way but most expensive is a machine shop. They will likely want to upsell you something.
The next best is is a press. Easy Peasy
The poor boy way is a with a hammer and a an old nut to protect the threads.
Drill and pin them if needed. Been done literally 1000's and 1000's of times to keep then from coming back out.

I've done them all at one point is time.

[Dave Koehler]

Just add to the mix, the old RM348 Pioneer is 7/16 thread and the head is already close enough to that tap drill size. Surely by hand one can easily tap it straight.

Almost forgot about those. Tapping straight in 2 planes can be a challenge for some but can be done.

Rfoll
I got curious and looked.
I still have a few new studs on the shelf.
If you want one, PM me with a name and address and I will mail you one.

[BillK]

I have a set of stock 305 heads I was going to use and noticed one of the studs was chewed about 1/3 through.

Rick,
Nobody else has asked so I will . . . . . why is it worn through ??? I am betting that it is one of the center studs and if you look at the hole in the head that guides the pushrod it is probably worn way out to one side. Carbon builds up around the exhaust crossover and pushes the pushrod sideways.

[dannobee]

Just add to the mix, the old RM348 Pioneer is 7/16 thread and the head is already close enough to that tap drill size. Surely by hand one can easily tap it straight.

That's the stud that I was thinking of that went with the summit tool that I mentioned to at least get it in straight. Did many like that without taking anything apart, other than taking off the rocker arms.

[rebelrouser]

Just want to mention, if he is going to do it himself, either press or by hammer, throw the stud in the freezer overnight, warm up the head a little with a torch, or heat gun, and it works a lot better than just beating them in at the same temperature.