# Pinned Rocker Arm Studs - Old School



## PontiacJim (Dec 29, 2012)

Before the more common screw-in stud used on Pontiac's high performance heads, rocker arm studs used to be pinned into place on high performance cars to keep them from pulling out. This was a common practice. The Hi-Performance heads on the 409 I ran had pinned studs, so many manufacturers did this.

Here is a photo of a 1961 Pontiac head, the Super Duty 389, having the studs pinned through the head boss. I circled the pin on the left pedestal for anyone who has never seen one or knew what they are. If you bought a "Kit" to convert your engine from a hydraulic cam to one of the McKeller solid cams (McKeller #7 or #8 ) for racing, the kit included the pins (part 177976) to retain the studs in the head.

I also pulled a page from my 1966 Crane Cams catalog with their Pontiac cam selection. At the bottom of the page is found the note about using their replacement rocker arm studs & nuts along with pinning the new studs on all heads except the factory equipped 1961-'63 SD 389/421CI heads listed.

This could still be done today if you did not have screw-in studs, but converting your heads to the 7/16" screw-in studs can be done very inexpensively and a better set-up all around. :thumbsup:


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## 1968gto421 (Mar 28, 2014)

Wow Jim, you have quite a library! Did you acquire the Crane catalog new or at a flea market. I have alot of old car/rod magazines from the early-mid '60's that I got on the news stand that I still have packed away. Thanks for the memories you bring back posting this historical stuff.


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## PontiacJim (Dec 29, 2012)

1968gto421 said:


> Wow Jim, you have quite a library! Did you acquire the Crane catalog new or at a flea market. I have alot of old car/rod magazines from the early-mid '60's that I got on the news stand that I still have packed away. Thanks for the memories you bring back posting this historical stuff.


I am not sure where the Catalog came from. I got it back in the early 80's, it may have been given to me by one of my buddies who was cleaning out "stuff." I began buying magazines on the news stand in the mid-1970's when I just got interested in cars. I probably have a collection of 500 magazines tucked away as you do. It was antique and the cars of the 50's I first liked. I used to have a big collection of model cars I built. Back then, kits were $1.99. Going to car shows with my dad when I was 16-18, I would walk right by some hot rod or "muscle car" and gravitate to the antique cars/original cars of 1950 & under. The car that got me hooked was the red 1967 Pontiac Firebird I bought from a buddy for $300. Had a warmed over 350CI transplant and factory 3-speed manual on the floor, buckets & console. The car was fast and could really put down some rubber. I was hit by the "need for speed" through horsepower from that point on and it has never changed.

My car & truck book collection probably began about the same time I got interested in cars and I have a big assorted library with my oldest published in 1910, many old technical books, some manuals, and everything in between as I like all the old cars. Now I don't buy many books or magazines because I have so much that covers most anyway, it really has to be something that sparks me for me to purchase nowadays.......and the prices are really absurd when paying $7.00 and up for a magazine. But I still pick them up from ebay, antique stores, and the swap meets when I see something of interest or unique. :thumbsup:


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## the65gto (Oct 9, 2008)

Mine were pinned after an "incident" where the oil pump pick up dropped out. I was at 100mph at a drag race. Oil pick up was tac welded in place during the rebuild. I thought I was one of the few who had pins??


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## bigD (Jul 21, 2016)

"...converting your heads to the 7/16" screw-in studs can be done very inexpensively..."


I suppose a price that is inexpensive to one, might be expensive to another. Since I always had to race on a low budget, even a $100 item was expensive to me.

From what I've read online, there are 2 ways to convert to 7/16 screw-in studs.

(1) Pull the old studs & tap the holes for the 1/2" bottom threads of the ARP 290-7201 7/16" studs, made for the purpose. Just found one set of these for $50.86, on Amazon. That's the best price I've ever seen. The price on most sites is around $90, or more. I've also read that the bottom threads of those studs are too long, therefore must be shortened. 

https://www.amazon.com/ARP-290-7201-Rocker-Arm-Stud/dp/B001T6CRDC

https://www.ebay.com/itm/290-7201-r...247721&hash=item2136c3d391:g:gW0AAOSwHYVaV2kr

https://thmotorsports.com/i-514619....LLakCFP-DSuTJ-SL7v9kEcadteOIvnOYaAjkMEALw_wcB

https://www.ebay.com/p/ARP-ROCKER-A...ONTIAC-1964-LATER/1611247721?iid=181555560104

https://www.summitracing.com/parts/...0TjtlVfXgryTvfYg-8pmfv43o7rIng64aAm6tEALw_wcB

Tapping the holes requires the correct tools & an accurate knowledge of exactly how to do it. Some can & have done this successfully, at home. But there have been reports of some holes that were tapped at the wrong angle. Probably not worth taking a chance on ruining a Pontiac head. So, for most, it is probably a good idea to pay a competent machine shop to tap the holes correctly. I assume this would cost $100+, at MOST machine shops. So, I'd guess that many have paid over $200 for the studs + labor. Lots of Pontiac screw-in stud core heads, such as 6x-8, don't cost any more than that. 

(2) Have heli-coils installed, and go with BBC 7/16 studs. Most new BBC studs are less than $50. You may even be able to get some used BBC studs real cheap, or free, if you have some BBC friends. But, you still have the cost of the heli-coils and labor to install 'em.

So, for those who, for whatever reason, can not do any of the work required to convert to screw-in studs, aprox how much will it cost to convert, using each method ? Any who have paid to have someone convert their heads to screw-in studs, please post your total cost, for labor & parts.


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## Shisida (Dec 24, 2019)

I hope someone can help with this: I have a pair of "15" heads that had pressed-in rocker arm studs. In giving them to my machinist to refurbish, he pulled out the studs, intending to tap them for screw-in studs. But he informed me that the holes were already 7/16", already to large to tap for the 7/16" thread of new screw-in studs. Is he correct that no larger-base studs are available? He seemed doubtful about trying to shoot in a helicoil as a solution. Thanks.


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## Mine'sa66 (Oct 30, 2019)

That's a nice flashback!
Built many small blocks back in the 80's and had the studs pinned.
Back then swapping in a small block was today's LS swap.
Usually on a budget, we'd bring the heads to the machine shop to be planed, pinned, hard seats, 3 angle valve job.
Viola! Race heads


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## PontiacJim (Dec 29, 2012)

Shisida said:


> I hope someone can help with this: I have a pair of "15" heads that had pressed-in rocker arm studs. In giving them to my machinist to refurbish, he pulled out the studs, intending to tap them for screw-in studs. But he informed me that the holes were already 7/16", already to large to tap for the 7/16" thread of new screw-in studs. Is he correct that no larger-base studs are available? He seemed doubtful about trying to shoot in a helicoil as a solution. Thanks.


ARP makes a stud just for this. Show this to your machinist. These are recommended by Butler.



https://butlerperformance.com/i-24452864-arp-7-16-x-1-2-rocker-stud-kit-arp-290-7201.html?ref=category:1281166



The other option is to pin them, BUT, if keeping the Pontiac "bottle neck" studs having the 7/16 lower shank and tapering up on the shoulder to a 3/8 " threaded end, they are not very strong if going with a higher lift cam and heavier valve springs as they can snap off at the bottle neck. So if you keep your valve lift reasonable and spring pressures to match, then you may be safe. Also would get the "long slot" aftermarket 1.52 rocker arms to add a little more clearance at the fulcrum slot-to-rocker arm stud if going more than stock lift.

The ARP studs above with the heli coils will give you the stronger 7/16" rocker arm stud and eliminate the weaker factory 3/8" "bottle neck" studs.


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