Missing Header Bolt Size?

[BlackZR1]

Good Evening guys,
What size is my missing header bolt? Looks like an M8 x 1.0 (fine thread) but I tried a coarse and fine thread and neither wants to start.

I also notice that the bolt below has a collar (like a 3/4" long spacer) on it. What is the purpose of the collar? Is this a special bolt?

For extra credit, what size is the small bolt that secures the aluminum cover over the throttle cables at the throttle body? The 2 nuts on the side are 4mm. My missing small bolt in front seems like it should be a 4 mm, but I tried a 4 mm and it didn't want to go.

Thanks,
Roger

[Dynomite]

Good Evening guys,
What size is my missing header bolt? Looks like an M8 x 1.0 (fine thread) but I tried a coarse and fine thread and neither wants to start.

I also notice that the bolt below has a collar (like a 3/4" long spacer) on it. What is the purpose of the collar? Is this a special bolt?

For extra credit, what size is the small bolt that secures the aluminum cover over the throttle cables at the throttle body? The 2 nuts on the side are 4mm. My missing small bolt in front seems like it should be a 4 mm, but I tried a 4 mm and it didn't want to go.

Thanks,
Roger

Header Bolt is 8mm x 1.25

Exhaust Headers Locking Bolt Tricks (http://forums.corvetteforum.com/c4-zr-1-discussion/3005470-tech-info-lt5-modifications-rebuild-tricks-500-hp-3.html#post1581564063)

I think the original accelerator cable clip screw....is a screw thread.....I think I just tapped those for a couple SS Allen Head bolts (I think 4 mm with a pitch of .70 same as TB Coolant Cover).
accelerator cable clip screw (http://www.jerrysgaskets.com/screw-accelerator-cable-clip-t-body-shield-new-90-95-6-5b/)

[WVZR-1]

Cliff is correct the accelerator cover fastener isn't a machine screw but a self-tapping M4.2-1.4X8 fastener. It is the same as the cable conduit retainers on the plenum if you needed a sample or wanted to confirm.

[A26B]

Roger,
If you have any difficulty finding the bolts you are looking for, we have a large inventory of LT5 OEM bolts.

Throttle Quadrant Cover Screw
http://www.jerrysgaskets.com/screw-accelerator-cable-clip-t-body-shield-new-90-95-6-5b/

Exhaust Manifold Bolts

The actual specification for the bolt is inclusive of the spacer you noted. I have always thought the spacer is to make getting a socket on the bolt head easier where the header tube is close to the hole. The M8x1.25 bolt can be sized to 25mm length if you use a socket head cap screw (allen head) of a reduced hex head header bolt. Not all exhaust manifold bolt holes actually had bolts installed at the factory, even though the holes are tapped. I think only 5 or 6 per side actually had bolts installed.

[Dynomite]

Roger,
If you have any difficulty finding the bolts you are looking for, we have a large inventory of LT5 OEM bolts.

Throttle Quadrant Cover Screw
http://www.jerrysgaskets.com/screw-accelerator-cable-clip-t-body-shield-new-90-95-6-5b/



No Jerry......it is called a accelerator cable clip screw (http://www.jerrysgaskets.com/screw-accelerator-cable-clip-t-body-shield-new-90-95-6-5b/) (Left Click on the Underlined) ;)

And I have to teach you Descriptive Links sometime (Left Click Links like in my Signature) :D

Oh....Jerry is the best on parts AND Packaging AND Delivery of parts no matter if I am in SD or CA it is always two days delivery with SUPER Packaging.

[mike100]

You aren't missing any hardware. The factory only used 7 (out of 16) mounting flange holes. Notice the rusty texture and no evidence of a washer, spacer, or bolt head flange ever being mounted there.

[RussMcB]

Roger, if it bothers you, and you think there is room enough to put one in, I can send you one. I just installed headers and used new bolts, so I have some old (original) bolts laying around.

But, like others have said, you don't really need a bolt there.

[BlackZR1]

Roger, if it bothers you, and you think there is room enough to put one in, I can send you one. I just installed headers and used new bolts, so I have some old (original) bolts laying around.

But, like others have said, you don't really need a bolt there.

Thanks Jerry, Cliff, Mike and Russ.
I have a big order coming for you Jerry, the little cover screw among them.
In checking that header bolt, I tried an 8mm x 1.25 like Cliff said then mistakenly dropped it into the header head shield. Arggghhhh!! I used a SS bolt so a magnet would not help retrieve it even if I could get contact with it.
Well if it is not necessary I won't worry about it.

Thanks again guys,
Roger