I have a 78 W200 with 400 ci engine and I'm trying to identify and source the correct exhaust manifold (bolts / studs / sleeves?) hardware for both sides. I've managed to find a couple sources online but because I don't know what the kit should include - exactly what I need - I am unable to discern whether it is the correct kit / correct parts or not. I have some specific questions and would also appreciate any help identifying and sourcing the correct parts I need. I can't just go about taking the old stuff off because the truck is my only vehicle right now and I need to minimize any down time. Not only that but there's a chance something will break and result in not having a complete old item to look at.

If its ok I'll list my questions and maybe someone could help?

1. In a single manifold... Are they bolts? Studs? Or some combination of the two?
2. Are they different from one side of the engine to the other? For example - is it studs on one side of the engine and bolts on the other or are both sides the same?
3. At least one (thing) plugs up a water jacket in the head (by design / from the factory design)...4. The two holes in the center position of each manifold are larger diameter than the head of the fastener (see attachment) that is in it (bold / stud) - is this where a "sleeve" is used?

And finally if anyone can direct me to a source to get new hardware for both sides (that either contains all pieces or combination of packages that gets me all pieces) I would truly adore that.

Thanks in advance for any help or guidance.

Jake

Its shaped like its counter sunk. Depth is probably around an inch or inch and a quarter (just to give some perspective). The hole at the bottom is smaller diameter then the diameter at the face (like something that is counter sunk or something).

With house key to give some perspective on size. The hole that passes through into the head (at the bottom of the larger diameter hole) is about half the diameter of the larger one.

Shows comparison to other (regular holes) - comparison of diameters between the holes in the center of the manifold compared to those at the extremities of the manifold.

Back side of the manifold showing all holes and with house key for perspective.

 

I don't recall because all my big blocks have headers(i used studs on all of them). Just look at the existing hardware.
The heads are the same so the hardware should be also.
All go into the water jacket.
It's possible that you may break more than one so plan ahead to drill and remove the broken hardware(easy out). You may have to drill it out and use a heli coil.

 

Thanks for the info. The reason I can't tell if it is a bolt or stud is because they are all so heavily corroded (there isn't even a defined edge of anything to get ahold of just a solid mass of corrosion) and there is no certainty I will be able to get even one of them off without breaking it. Really what I was hoping was to source something that gives me hardware that will work - work with the parts I'm using (ie: manifolds not headers), and that handle the water jacket thing appropriately - proper parts or kit. Then I won't care what's in it now only that I have everything I could possibly need (and the right things that will actually work properly) on hand before I start the job.

I've called exhaust shops and machine shops and everyone I've talked to so far has treated the question very flippantly giving me approximations on what to use and talking like it didn't really matter - but I can not afford to have the wrong pars / hardware sitting there when I tear into this thing and lose the ability to drive the truck.

 

If you break the stud/bolt are you able to fix in the vehicle?
https://dantesparts.com/c-1389269-ou...-hardware.html

 

Well, yeah. I mean I have never done it before but i understand what has to happen and what to watch out for. For me having parts on hand has been the bigger concern. If i have what i need on hand then i dont have to worry about it not being available and the truck being in a non driveable state. I can deal with doing the work. I cant deal with having the truck disabled.

Thanks for the link. I'll look at that.

 

I just called the guy at the site you linked and he was telling me that the stuff he has is for cars and he doesn't have any way to cross reference (find out) whether the hardware he sells would work for a truck. He says he can't be sure if the "thread size" is the same or not (where the stud/s go into the head). I asked him whether that same heads are used on a car with that size engine (the 400 big block) and he said it is but still said that he has no way to be sure about the compatibility. He also said something about needing to know what "sleeve size" for something - which I'm not sure how to get that info for him - I wasn't sure what he was asking. Could that have been the length he was asking for?

I guess I need to verify or be certain that that my truck can use what he has and answer the question about sleeve size?

Thanks

 

In case any future reader comes across this and may be helped by the information...

I finally found out what I needed (and getting there was pure hell let me tell you). After exchanging half a dozen messages with a seller on ebay I was finally able to dig out the SPECIFIC information that he needed from me. Here is the relevant part of that person's initial response.

Thinking that by "size" he meant what size wrench fits on the nut I obtained and gave that information (which was not what was being asked for). It turns out we needed the length for the longer, sleeve nuts. I was also asked for the length of the studs.

For my application (and I'm not sure if the engine in it is the original engine or not) it is the 3 inch sleeve nuts and the part of the stud that sticks out of the head is 1.25 inches.

--------------------------------------------------------------------------------------- TLDR ---------------------------------------------------------------------------------------

It turns out that in my case I needed 4 of the 3 inch sleeve nuts (two for each side), 8 studs (four for each side), and 8 regular nuts (four for each side).