ARP head bolt #

50C8DAN

Does anyone know the correct ARP head bolt number for the 308?

GrimGreaser

Want essntially the same bolts at a easier to swallow price?

McMaster: 

1/2-13 3in long 12-point head bolts : 91271A724 https://www.mcmaster.com/#91271A724

7/16-14 2.5in long 12-point head bolts : 91271A679 https://www.mcmaster.com/#91271A679 (longest they have in that head style)

Glowplug

Grim:  Great 3 D printing products!  

Geoff

Paul Schuster sells these bolts and hardened washers.   Great value. 

RichardD

Can't put slip-on chrome acorn caps on 12 pts.  ha~~

GrimGreaser

These are great too:
https://www.mcmaster.com/#92316a656
https://www.mcmaster.com/#92316a724

Not alloy, but Grade8 is more than sufficient for these engines.

Don't let me de-rail the thread...  But here you go OldFarmer:

Glowplug

Sweet.....   thanks....will swipe this picture and add your URL to my website!

bob ward

The originals would have been grade 5, grade 8 bolts as has been said will suffice.

50C8DAN

Darn they come in sets of 10, and of course you need 21!  Thanks for the sources and types

50C8DAN

Found these places that has 3" 7/16"-14 Flanged Grade 8s

https://www.flangebolts.com/shop/7-16-14x3-hex-flange-bolt-grade-8-phos-oil-11145

https://www.boltdepot.com/Flange_bolts_Partial_thread_(IFI-111)_Grade_8_steel_plain_finish_7_16-14.aspx

And these 12 points:

https://www.aftfasteners.com/7-16-14-x-3-12-point-flange-bolt-plain-oil/

50C8DAN

Anyone want to go in on some head bolts?  The flanged grade 8, 7/16-14 x 3 inch bolts are only about $0.71 ea in quantities of 30 including shipping.

m.patterson56

I might be opening up a can of worms here and I'm sure people have been over this subject again and again. Some people say studs/bolts all the same thing, but I was told that the reason for studs with nuts was that the fine thread would be a little dicey in the poorer quality engine blocks and the coarse threads would hold better in the block and not tear out. Having a finer thread on the outer end of the stud (with a washer) would then allow you to apply greater pressure on the head without turning the stud in the block. Then the coarse threads are not disturbed and the forged fine thread studs and nuts take the abuse instead of the block. No?

m.patterson56

Lovely gauges by the way! Where can I get some?

50C8DAN

https://www.thomasnet.com/articles/hardware/head-stud-bolts

ski4life65

I bought my 7/16 bolts from CAT. The head is 11/16 instead of 3/4 but it is close enough that it isn't really noticeable.
 https://parts.cat.com/en/catcorp/hardware-and-fasteners/bolts/4F-5192

Kdancy

https://www.mcmaster.com/#standard-hex-head-screws/=1ayqqms

Mcmaster-carr is my "go-to" for most hardware. ARP for more specialty ones.
You can call order in or order online. Quick shipping.