K guys I need help finding a special part

[geoffinbc]

I need a rocker arm stud that is M10X1.25 on the bottom and 3/8-24 on top. I need the distance from the base of the stud nut to the tip of the rocker stud to be .750 or greater in length.

Think of your typical 60* V6 conversion stud but longer on top.

ARP does have this application but it has a 7/16" top and my rockers are not avalible in that size. They also have one that has the right top but the wrong bottom. I have checked Crane, Comp, ARP and Cammotion. I dont know where else to look. I really dont want to drill and tap the head. But I may end up drilling the rocker arm if I must and use the conversion studs for a BBC.

If you guys know of a source for specialty studs and fastners or a maker that may just stock these that would be sweet.

[mcgavinz26]

Do any of those guys make the parts in house? Maybe trying calling them and seeing if they can just machine the combo for you. You seem to know your stuff pretty good though, so I'm guessing this isn't an option for some reason. So this post probably isn't very useful to ya.

[geoffinbc]

Well Im hoping someone has seen what I need out there. Hence the thread

ARP should make them I will call them and bring up the idea to them. What I am doing is installing Self Aligning Pro Magnum rockers on a 96 to 99 4.3L Vortec V6. The rockers only come with a 3/8" hole and the heads have a M10 hole. Newer 00+ Vortec heads have an M8 hole and ARP sells a stud for them. ARP also sells the 60* Conversion stud but it is too short So if they just make it 1/4" longer they will have a new product.

[1988GTU]

See if you can get a few people to group buy from ARP for the 1/4" longer stud.
That might getcha those studs. Just my .02.

[v6h.o.]

Ah... Cranes are 10MM X 1.50 BOTTOM X 3/8" X 24... Fuck difference by .25 thread pitch eh.

What are these going in?

[Guest]

BTY, the Pro Magnums are the fully extruded Aluminium boddied rockers, correct?

I used Stock 660 Studs on a '99 Vortec 4.3, but we used the Magnums, the roller tipped rockers.

*Edit* I just looked at the Comp site, not exactly the ones I was thinking of, but require teh same style of stud and nut I was thinking of.

Just curious, is there any stud protruding through the fulcrum, when the rockers are set on the existing (readily available) studs? If so how much?

[geoffinbc]

The truck is a 97 4.3L Vortec. The studs dont even stick out of the rocker fulcrum enough for the threads on the adjusting nut to catch. Right now we have 60* Conversion studs. They are just a touch over 1.5" from the base of the studs nut to the tip. They need to be 1/4" longer. 3/8" longer would be great for a little more thread contact.

I have already done this same rocker swap on a 2002 Vortec 4.3L. However we used ARP's LS1 rocker conversion stud with an 8mm bottom and it has a 1.750" length which was great and we have plenty of thread contact.

[geoffinbc]

Well I phoned ARP and they don't seem to be interested in producing it. I told him that a stud like that would cover all Vortec motors up to year 2000 It would also cover any iron head Vortec motor with stamped rockers too. He said to me that most people using that head would tap out the the head to a 7/16" stud. Well sure thats easy when the head is off the motor. But I am sure if anyone had the option of the correct stud they wouldn't bother. Taping all the stud holes is a lengthy process and can only be done off the motor. The hole for the rocker stud on these motors protrude into the intake port. So doing it on the motor is NOT an option.

Well if you guys can come up with any leads on someone who would produce a part like this and would be interesed in being the only manufacturer on earth with a stud for this application they should suggest the idea.

Does anyone know how hard the truntion material is on these roller rockers? I could use Big block conversion studs and drill the rocker body to accept a 7/16" stud. My last option is to go to a 7/16" rocker body which is only avalible as NON Self aligning and install guide plates and hardened pushrods.

[XLR8ING]

I talked to a place here in London, Ontario once about custom rocker studs, and they said they could do it. I got a better deal on my ARPs though. But it was just a local fastener shop, and cost about $8 each CDN.

[geoffinbc]

Thats actually not a bad price considering it is custom.

However we have a solution now. It is not as good as the Pro Magnums but its going to give us the 1.6 ratio.

I got rockers off my buddies 3400. We knocked off the pedistal and used a late model vortec guide bar (which is used on 4.3L's with factory roller rockers) and drilled it out (it's just aluminum) to pass the 10mm bolts of the 3400 rockers. We drop everything in and torque it down. Bam 1.6 ratio roller fulcrum rockers at no cost!

[geoffinbc]

Well Back to square 1. That plan failed.

The 60* V6 rocker has a fulcrum that is .100 higher than the 4.3L rocker. It also has a larger diameter fulcrum. So the 4.3L guide bars wont work. So what we are going to do is produce a new guide bar that is higher and has a larger diameter saddle to hold the 60* rocker arm. I have a friend who is gonna make a run of them so I can sell them to other 4.3L owners.

Also I have contacted a local machine shop that specializes in prototypes and production work. I gave them a drawing and they are gonna quote me. I will have them made to Grade 8 spec (160,000PSI) so it will be plenty strong.

There is one side benefit for us 60* owners. If I get the stud produced the longer length will be ideal if anyone ever wants to install a stud girdle.