I just called ARP and spoke to Debbie about this. It seems that the block from the factory doesn't tap the hole the entire length and a gen. III tap is necessary for chasing all of the bolt holes. The part that is required is part # J42385107 from Timesert. It seems it's necessary for milled heads --- stock unmilled heads may get by without it..


Wayne

 

More infor on the dealer who re-uses old head bolts.

He is located in Scarsdale NY; He is a medium sized dealer that has been around for decades....

He asked me why I was ordering new head bolts for my H/C swap. He said he does not carry them in stock and that I am wasting my money. He claims to do lots of warranty work involving engines and has NEVER used new TTY bolts.... Apparently, no problems in many years...

I also asked an engineer about TTY bolts. He said bolts do stretch but not that much and the steal is ussually very strong....He thinks it is a gimick to sell morre bolts too...

I also read somewhere that in a pinch it is OK to reuse the short head bolts and also the crank bolt..... I think this was stated by a sponsor --------->

 

Had my car **** coolant with milled heads and ARP bolts

 

I hope my bolts hold. If you would have posted this post about one week earlier, I would have purchased studs. Oh well, I will find out once I get my intake and tb on.

Pray for me.

 

Regardless. When he does warranty work, GM CALLS FOR NEW HEAD BOLTS, and he is being paid for them. Not to mention the ticking time bomb this causes. I would run far away from the dealer, and personally would report him to GM.

 

I checked my ARP head bolts to a set of 5.3 stage II.5 heads "not milled" and the very back one on both sides seemed not to wanna go all the way in "about an inch too long" I also cleaned all holes and blew them out as well but the second time around they did go in without a problem. After reading this is when I pulled them all back out and called ARP them selves. They are putting together something so future sales will include this tool or be offered with it. I'm upgrading my bolt to studs and will get the tool as well for friends to use or borrow.. I'll keep this post updated as they are calling me back tomorrow on the status of the tool.

Wayne

 

It's not proper mechanical assembly etiquette. I have several ASE Engine Assembly certification manuals that say in BOLD type to NEVER re-use TTY bolts. They're designed to be stretched to their final torque holding. Once they're loosened they don't recoil hence you can't restretch them to hold the proper torque, period.

It is flat out INCORRECT to reuse ANY TTY bolt, regardless if someone reuses them all the time with no issue. I believe mechanical engineers that designed these type of bolts are a little more in the "know" with what these bolts can and can't do vs. a mechanic who has snubbed the teachings of his/her ASE certification.

 

Torque to yield bolts are designed to stretch and and actually "pull" the head to the block. They are only designed to stretch one time. Further stress on the bolts will result in compromised clamping and worse yet, failure. You can not re-used them, period.

 

i measured my ARP head bolts to my GM headbolts, they look like they are the same length (with the washer on the ARP). still not sure why i was leaking coolant....my heads are only milled .010

 

Had a customer report to me last week that he snapped the head on one of the ARP bolts, could be he bottomed it out and didn't realize and the head snapped. I have heard of this before on a few other cars as well

 

Does anyone have the size and pitch? I was thinking of going with ARP's and need that info if I'm going to chase down a tap here locally.