Manifold bolts?

[FirstRide]

Why would the manifold bolts be not very tight and also the picture that I attached is that a factory manifold bolt?

[Ironhorse]

Most likely many years of heating (expanding metal) and cooling (retracting metal) could possibly cause the manifold bolts to loosen. Also there is a specific torque setting for manifold bolts. Two schools of thought also for manifold bolts, run them in dry or use anti-seize on the threads. Personal choice there. The bolt pictured can well be a original manifold bolt/stud combination. Used as a grounding stud or attachment point for a specific bracket of a specific engine/year application. Have seen them used on thermostat housings also. Others may have more info but that is my 0.02 worth.

[Gromit]

On a Small Block Chevy 350, the manifold bolts are 1.25" long (at least on mine - mine has an Edelbrock 2101 Performer manifold so not stock) -

But that bolt in your photo looks a lot longer than 1.25"

Unless it is one of the thermostat housing bolts (that is also on the manifold; but isn't a manifold bolt per se).

Anyway, here is a photo of a good manifold bolt set - pretty much worth the ten bucks in my mind because with the 3/8ths" 12-point head there is better clearance for your torque wrench on those bolts in the center of the manifold (other wise you can only turn a regular hex head bolt about a quarter turn at a time and definitely no room for a torque wrench)

[Mmorgan32]

If that's an exhaust manifold bolt I have the same problem. I tighten them every once in awhile just haven't gotten around to buying new ones and I am alittle paranoid that there will be one the will snap on me

[leddzepp]

Looks like an exhaust manifold bolt, driver side. The stud is where the OEM heat stove attached over the top of the manifold.

[Phildeez]

It looks like one of the exhaust manifold bolts I have. It bolts through the ac compressor mount and the manifold. The bolt closest to the front on the passenger side.

[FirstRide]

Thanks for all the replies the reason why I asked why they may be loose is because the truck has been sitting for a good 5 years or more so I figured they be rusted in there pretty good.

[kenn]

Hello
I think leddzepp is correct, That looks like my exhaust manifold heat stove bolt.
The A/C bolt is 3/8" on both ends and the short end is a little longer then that looks.
K.E.N.

[FirstRide]

This came off my passenger side

[FirstRide]

I have to replace one manifold because of a crack in ir. Would it be best to replace them both along with the manifold bolts?

[tcrist]

If you do not need the extra threaded part of the bolt you can change to the Stage8 bolts http://stage8.com/. Locks them in place. Not sure if they have them for stock manifolds or not. They have them for headers though.

[PatrickGMC70]

Originally, the exhaust manifold bolts had little horseshoe-shaped retainers under the outside pairs of bolts. They had tabs that folded over to keep the bolts from backing out.

They're still available in catalogs, but my memory from the last time I looked is that they were pretty expensive ($20 or so) for 4 pieces of cut sheet metal. I suppose you can justify it by the old "if you need them where else are you gonna get 'em" theory. Plus, it's not like you're taking the manifolds off all the time and have to constantly buy replacements.

[71CHEVYSHORTBED402]

Heat stove bolt huh? Didn't know that. The stove mounts to the manifold in two places. At least for the BBC. Safe to assume they are two of the same bolt, BBC and SBC?

[FirstRide]

What type of headers are reasonably priced and will fit a 1971 c10 lwb with a 350 and a three speed cloumn shift that will fit all that?

[Jason Banks]

Originally Posted by Phildeez

It looks like one of the exhaust manifold bolts I have. It bolts through the ac compressor mount and the manifold. The bolt closest to the front on the passenger side.

If it is the manifold bolt that also works with the AC compressor mount, you can still get them from GM.

[seattle gmc]

the stud pictured is for the heat stove riser tube assembly. The horse shoe locks that came originally are called french locks. The repop ones are bigger then the orignal ones and dont fit well. The french locks were only used for outer studs on the each end of the manifold. I ruined the original ones on my truck when i removed the cracked manifold on my truck.

[leddzepp]

Here is a pic to show which bolt goes to which part. On the left is a heat stove and the same bolt as the OP posted. On the right is the lower AC bracket and the longer bolt/stud mentioned above. These are OEM small block parts.

[seattle gmc]

Hey led zep,

My heat stove dose not have those two big holes. Did yours come that way from the factory. To drop the driver side manifold i first have to split the monifold stove assembly in half to get to the center manifold bolts outs. Easy enough coming off, but a pain in the A** putting everything back together.

[leddzepp]

The one I have pictured is from a 4wd truck, I'm guessing your truck is 2wd.

[FirstOwner69]

Here's a picture of my 350 with the stud bolt installed for the A/C compressor bracket and the correct French locks mentioned in a couple of posts above.

[seattle gmc]

I got a 4wd. But myheat stove lacks those two holes and dose not have the indent. It only has the little hole for the stud to poke through. The two halves are held together with several small sheet metal screws.

[leddzepp]

Here is one that I removed from a 2wd. It does not have the two larger holes in it. It also has a slight curvature to it for the angled manifold. They both attach the same way with a backing plate and small screws.

[seattle gmc]

Thats exactly like how mine looks. I will take a closer look later on and see if it curves at the bottom. Being that my truck is a 4wd with straight dumping ramshorns, could their have been a mistake made durring assembly, and my truck got that wrong heat stove? The thing was a real pain to get back on, i had to bend the back half to get around the manifold.

[tk1251k]

Originally Posted by FirstRide

Why would the manifold bolts be not very tight and also the picture that I attached is that a factory manifold bolt?

I know this is an old post but I was just looking and I just removed the intake for my 72 350 totally stock engine. That bolt is passenger side intake manifold bolt and its the 4th hole back from the front of the engine just behind the choke heat stove.. The electrical thingy attaches to that not sure what it is about1/4 diameter and 2 inches long with two wire. It attaches with a nut and goes to the smaller threaded end of the bolt.

[Andy4639]

Originally Posted by Phildeez

It looks like one of the exhaust manifold bolts I have. It bolts through the ac compressor mount and the manifold. The bolt closest to the front on the passenger side.

Correct sir! I have the same one in my AC brackets.