Exhaust manifold bolts

[PGreenSVT]

I want to replace the oem bolts with ARP stainless studs when installing my Steed Speed manifolds. Can somebody verify that the bolts are 3/8-16?

[Six0~Stroker]

to the heads?

[Six0~Stroker]

Just talked to Tousley, they don't know the size

I do have some of those bolts at home and will be able to check tonight If you don't get an answer sooner.

[PGreenSVT]

Yes, Manifold to the heads. I am pretty sure that is what they are. Just thought I'd double check before I order them.

[windrunner408]

I can pretty much guarantee that they are not 3/8-16. IIRC, they are metric. Like M8x1.0 or 1.5 or something. I replaced my exhaust manifold bolts when I did my head studs with grade 8 bolts. Unfortunately, I don't remember the size but I presume that since the intake manifold bolts are metric (M6x1.0) and every other bolt on the motor (except for v-band clamps) seems to be metric, then I am also guessing that the exhaust manifold bolts would be no different. Again this is just a hunch at this point. I will go home when I get off work and see if i can find the old bolts as I think I still have them and I will check.

[JUGERNAUT]

6 mm 1-------13 Nm (10 lb-ft)
8 mm 1.25----31 Nm (23 lb-ft)
10 mm 1.5----62 Nm (45 lb-ft)
12 mm 1.75--107 Nm (79 lb-ft)
14 mm 2----172 Nm (127 lb-ft)
15 mm 2----216 Nm (159 lb-ft)
16 mm 2----266 Nm (196 lb-ft)
18 mm 2.5--368 Nm (272 lb-ft)
20 mm 2.5---------------same

i think they are 8mm or 10mm i will find out for him in the a.m.

[06powerstroke06]

they are 10mm bolts

[windrunner408]

Well I found my old exhaust manifold bolts and I checked them with a tap and the threads matched M8x1.25 and when I mic'd the with a pair of calipers, I got 7.91mm. Hope this helps.

[JUGERNAUT]

Originally Posted by windrunner408

Well I found my old exhaust manifold bolts and I checked them with a tap and the threads matched M8x1.25 and when I mic'd the with a pair of calipers, I got 7.91mm. Hope this helps.

yep there 8mm 1.25 bacause the torque spec in book matches a 8mm bolt

[PGreenSVT]

The only metric stainless studs ARP makes are 8mm x 1.25 so I guess that's it. $154.74 for 16 studs and nuts. WTF is up with that?