TTY head bolt ID

[3500GMC]

The 6.2 I have was reman'd at some point, pulled one of the heads to check for issues and was wondering if I have TTY bolts or aftermarket bolts.

The one with the '11.9' is what held the 6.2 head on. Can I reuse these or are they TTY?

The one with no markings and long threads is out of my '93 6.5 that went poof a while back.

Not sure which ones to use.

 

[bk95td]

The only non-tty bolts I've heard of for either 6.2 or 6.5 were ARP bolts. They would clearly say ARP on the head of the bolt. I wouldn't risk it. I prefer the arp studs.

 

[6.2 turbo]

My 6.2 had the 11.9 bolts,6.5's use 10.9,I'm thinking the new ones are all 10.9 . I reused all my 6.2 head bolts,and torqued them untill they just stretched ,somewhere between 130 and 120. I had Victor gaskets and they held 30 - 45 psi boost for about a year,when I hit 60 psi the head gaskets blew,I don't think the 11.9 bolts are all that bad. I am seriously considering using them in my 6.5. Same deal on the bottom end, 6.2 has the better bolts . Bill Heath torques the ARP studs to 120 , you can easily get that out of the 11.9 bolts.

 

[3500GMC]

Did Felpro offer a non-TTY bolt? ES72724?

I am wondering if one of the two sets I have aren't the Felpro's...

What does GM's TTY bolt look like?

 

[uniquediesel]

The threaded area is what stretches. The one on the right can be re-used.

The torque is only 88-112 Ft. Lbs.

 

[625fireman]

IIRC bolts with #'s on top are the hardness rating for metric bolts. As for reusing them IDK. Personally I would go with ARP studs for sure.

 

[Missy Good Wench]

To the best of my knowledge the bolts for these are all TTY.
The studs by ARP and a few others are reusable.

Missy

 

[randomid25]

Don't skimp here. Just pay the 50 bucks for new head bolts and change them all out. Its not something i would prefer to redo later.

 

[Acesneights1]

I have reused head bolts on a 6.2 as well but I would not recommend it. I was in a jam.

 

[THEFERMANATOR]

Both of those bolts are TTY stretch bolts. You can see the step in them at the neck. And it's not the threads that stretch, it's the shanked portion.

 

[Acesneights1]

How tight do you torque the nuts ? 110 lbs ?