rusty65

As a few of you know, Ive been in the process of building an 89 302 HO for my 65 coupe. Well, i bought new ARP main cap bolts because i was told that most of these high quality fasteners are "only good for one stretch" and i figured hell, with how much money ive got into it a little extra bottom end security is cheap at ~$30 a set. However, I am concerned that the bolts i bought may not be the right ones even though summit says theyll work. The reason for my doubts is that when i received them in the mail and opened them up the instructions that came with the bolts say to torque them down to 70 ft/lbs (like a normal 302) but my manual says that HO 302's need to have the main bolts torqued to 105 ft/lbs. My greatest worry is that if i dont torque the bolts to 105 ft/lbs ill have problems once the motor is up and running, and that if i do torque them to 105 ft/lbs these bolts will snap... Any thoughts?

frdnut

I would call ARP and ask them..Don't rely on someones "opinion" as to what you should do.....I was having issues with a headgasket leak and called ARP regarding head bolt torque..The ARP torque in the instructions included with the bolts was lower than the stock headbolt torque(with aluminium heads)...After talking to the tech guy he told me they had revised the torque numbers and to go with the stock values....

67mustang302

Torque numbers for the same bolt also change depending on whether they're dry, coated, coated with oil, using moly grease etc etc. The same bolt could have 5 different torque settings for the same thing depending on what's on the threads during assembly.

Call ARP and ask.

Keep in mind, factory torque spec is probably for something like a Gr8 TTY bolt with no washer or coating, and oiled threads. Whereas the ARP bolts are a coated bolt with moly lube that are CrMo and not TTY.

JMD

Torque values also change when course threads are changed to fine threads, as is the case with every set of ARP STUDS I have ever used... (the nuts are fine thread)

Of course if you are using BOLTS and not studs.... Never mind....

67mustang302

Capscrews actually. Technically it's not a bolt unless there's a nut on the other end. If it's the bolt without the nut, screwed into something, then it's a capscrew.

1slow67

I torqued all mine down to about 70-80 lbs on my 87 HO motor.