ARP Head Studs 86-7 questions on thread length

[TR Custom Parts]

Getting ready to put my refreshed Champion irons on my new short block and decided to go head studs this time around instead of the ARP head bolts. Noticed something weird about thread lengths on the block side. The middle size and longest size have the same thread length. The shortest studs have one with the same length as the other sizes EXCEPT all the the rest of them have shorter thread length. See the pics, were these made on a Friday? Shouldn't all the studs have the same thread engagement in the block?

 

[1KWIKSIX]

As I recall, I had to double up on the ARP washers on those 2 longer studs on each cylinder head. If you do a search on these ARP studs you’ll find lots of posts regarding this .
Chase those threads & then
Clean those threads in the block carefully ( not sure if I used lacquer thinner or brake cleaner) using a small bristle brush & blow dry with compressed air. I also used Permatex Aviation Form a Gasket Sealer on these studs going into the block with excellent results .

Here’s a link on a thread of the same subject :

S

Thread 'Head Gasket Install W/ARP Studs....questions.'

Feb 17, 2020

Hello, first time doing head gaskets on my GN. I'm upgrading to Champion irons and ARP studs during the rebuild.

Here's what I know to do:
1. Hand tighten the studs
2. Use thread sealer on studs that go into coolant passages
3. Verify torque value after studs "settle" roughly three hours (or so) after initial torque
4. Use ARP supplied lube to achieve torque value
5. Chase the threads before install with 7/16 - 4 chaser

Here's what I'm not sure of:
1. I'm using the GM graphite head gaskets (PN: GM 25528486) do I need to coat with copper spray prior to install?
2. Where do the short...

• Stamos
• Replies: 17
• Forum: General Turbo Buick Tech

 

[dynoman]

Loctite 567 is a great thread sealant for head studs . I've never had an issue with it.

 

[pacecarta]

forget sealer did you look at the pics of the studs , the one is wrong maybe for a hotair block, send them back