Stock & ARP Head Fastener Sizes?

[daren_p]

Was wondering if anyone could verify the stock head bolt size and the size of the ARP head studs? I don't have metric 12 point sockets for the stock bolts but it looks like they are 12mm? Unless the ARP nuts are Metric, they appear to be 1/2"?

 

[95blackGsTurbo]

ARP are metric 14mm 12 point.

 

[project_tsi]

Your stock 7 bolt head bolts are 12mm 12pt heads, 11mm diamater.

6 bolt head bolts are removed with a 10mm Allen head driver.

7 bolt ARP head studs are 13mm 12 pt. nuts, 11mm diamater studs.

6 Bolt ARP head studs are 14mm 12 pt nuts, 12mm diameter stud.

You need a 12pt, 12mm socket to remove your OEM head bolts.

 

[daren_p]

ARP are metric 14mm 12 point.

That isn't correct for the 7 bolt studs, atleast not mine. Are you sure about ARP being metric? While 13mm will work, 1/2" is slightly smaller and fits the ARP nuts perfect. Yes the stock 2g's are 12 mm.

 

[sleepy98gsx]

in my experience with the ARP's in my 7 bolt the nuts are a 12 point 13 mm..fit perfect for me and fastened fine..

Chris

 

[95blackGsTurbo]

I forgot to mention I was talking about 6 bolt studs. I thought you had a swap because in the last post I helped the guy did a swap. Simple mistake. And how is that wrong. The wiseman under me said the EXACT same thing.

 

[daren_p]

I forgot to mention I was talking about 6 bolt studs. I thought you had a swap because in the last post I helped the guy did a swap. Simple mistake. And how is that wrong. The wiseman under me said the EXACT same thing.

It wouldn't be wrong if we were talking about 6 bolt studs because they are apparently 14 mm, but we were talking about 7 bolt, so that isn't correct info . The wiseman didn't say the EXACT same thing as you, he stated both the 7 bolt size which pertains to this post and also the 6 bolt size for reference, but had each one labeled.

 

[TalonSpeed]

The correct sizes are not metric. On my old regular arp for a 7 bolt, the nuts do not have any marks on them. A 13mm 12pt will strip if you dont hold it perfectly steady. The correct size that fits the best is 1/2 12pt.

My L19s newer nuts have 7/16th (stud diameter I think) written on the side but a 1/2 12pt is needed. Using this size I was even able to remove badly stripped nuts.