rocker shaft studs

Looking for rocker shaft studs for a 360 LA motor. I see Mancini and Hughes sells an entire kit, but mainly just looking for the studs. Studs should be 5/16-18 and 2.25" long, but can't seem to find any. Anyone know of who may have them? I searched ARP site but couldn't find anything.

Summit sells about any stud size you may need.

Don't buy the mancini stud and hold down kit. I did and while the hold downs were great the studs were horrible, most of them were not straight and the slot for a flat head screwdriver in the end of them was soft and tore up easily. Hold downs were awesome though.

Sorry I am no help on the 5/16" studs. I have bought ARP 3/8 studs for some race W2 stuff but I suffered through the mancini wobble studs for my old LA heads.

I found these on Summit Trick Flow P/N: TFS-70000100-204. They seem like the would work, I asked the Summit Tech guy and he said they are for Mounting the upper and lower plenum together on a ford and woudln't recommend them for what I want to do. But I think those guys just go off of what their search find and don't recommend something unless it specifies it. So would they be strong enough for what I want to do? Would a grade 8 stud work?

$15.99 each x 10......

Summit has ARP studs. Just search for the size you need.

What about these from McMaster-Carr? They are rated at 150,000psi(Grade 8) pending your spring pressure.

actually they are 15.99 for 4.

A while back I went through this with 5/16" studs. I was not successful in finding anything that was long enough to pull down the rocker shaft and have enough threads not to bottom out before it was tight.

If you are successful please share the solution.

Thanks,
Bill

Did you happen to try any of these, this is what I have found so far...


ARP 200-2402 1/2" course, 1 1/2" fine, ball nose 1/4" 2.7" OL chromoly 170,000 ($16 for 4)

Dorman 675-094 1/2" course, 1 1/2" fine 2.5 OL Grade 8' ($9 for 10 )

Trick Flow 70000100-204 2.25 OL ($15 for 4)

Duster Kid,

It has been a while ago and I don't remember other than at the time, I could not find an ARP stud that would work.

I did Internet searches for others but did not find anything.

If Clark (Bad340Fish) still has a Mancini stud maybe he can measure it for us.

Bill

Just go with ARP

I ordered a pack of the Trick Flow to try them out. They are made from same material their BB rocker arm Stud kit is made from, from what the Summit Tech guy told me. I would like to go with the ARP ones, but with only 1/2" of threads, I don't feel that is enough, I think the Trick Flow have more threads, but will find out and report back my findings.

With a problem like this I usually order one set of everything I can find and then see how they actually work. I've learned over the years that most descriptions and pictures on the internet are wrong, incomplete, out of date, etc. So now I just order the parts and figure it out for myself if they'll work or not.

Duster, are you running aluminum heads? If so carefully measure your thread depth. Make sure to get as much thread in the head as possible. If not assembled yet I would advise running a bottom tap in each hole to get a couple more thds engaged. Have seen bolts and studs pull threads out of aluminum heads. Because of not enough thds engaged. ARP will have just about anything you need. Good luck to you!

Yes using Edelbrock heads. I can't seem to find a stud with longer than 1/2" of threads to go into the heads, is that enough? Factory bolts are closer to 3/4" if I remember right.

Update:

I called ARP they don't make anything with more than 1/2" course threads unless they custom make it.

I did order a pack of the Trick Flow P/N earlier in the week (they have just a tad over 1/2" of threads) and have been mocking things up, but didn't feel there was enough thread in the heads, but on the way home from work today I got to thinking. On my Edelbrock heads anyways the threads for the rocker shafts don't start until .40" in the hole.

With the factory bolts there is .871" of bolt under the shaft resulting in .471" of thread engagement.

With the Trick Flow studs there is .918" of stud under the shaft resulting in .518" of thread engagement.

So the Trick Flow studs have .047" of more thread engagement. For some reason I was thinking that since the bolt had .871" of threads showing under the shaft I needed atleast that much on a stud, but in reality, not all the threads are being used.

The overall finish on the TF studs isn't as nice as I'd like, so I did order a set of ARP studs that are to be delivered tomorrow (should of taken AndyF advice and order both at same time). I'll mock them up and see how they compare to the TF studs.

My machinist ordered mine individually through arp years ago for my E-Brocs...........

Another update:

ARP studs arrive, nice quality as always from ARP. Let they said only 1/2" of course threads. Due to the 1/2" length, the amount of threads into the head is about 2 threads less than a factory bolt. Not something I'm comfortable using, so I tried the Trick Flow Studs since they are 5/8" course, which is adequate, but since they are only 2 1/4" long, it only leaves .120" for a nut, which isn't enough IMO. So for now I'm just going to use the factory bolts. So if anyone happens to run across 5/16 studs with 5/8-3/4" course threads that are 2 1/2 - 2 3/4" long, those would be idea for this and please share as I'm sure I'm not the only one that would buy a set or 2.

Did you call ARP? If not, call the tech line and tell them what you are trying to do. Give them the part number of the studs that you ordered and ask if they have some with more threads on the course side.

I did call ARP tech line and explained what I was looking for and the guy said they only have 5/16 studs with 1/2" on the course side. Said I could call they manufacturing line and request custom ones be made, but that would be $$$.

McMaster-Carr 90281A112

2.5" OAL 1" thread on both ends