Most likely a stupid question and a search didn't turn up what I was looking for.

I'm building a 300 I6 and am at the point of installing the exhaust and intake manifold (stock). The engine as I received it did not have the manifolds, so I bought new ones. I thought about aftermarket but want to keep it stock (except for the ignition and lack of computer...)

In any case;

There are no studs to connect the intake to the exhaust manifold. What thread size / pitch / length do I need to source?

The intake manifold I have also has two threaded holes just below the carburetor mounting surface. One is for the vacuum 'tree' that supplies manifold vacuum (I assume). I have no idea why there is a second one. I assume I just need to plug it?

I have the service manuals, but they aren't much help in this case.

Any help out there? I'll try to get some pictures if needed, but just for grins, this is the engine to date, sitting on the test stand (the stand is in progress as well)

 

Hi -

Thanks to help from FTE members, Hillco Fasteners has the studs you need. Check out Home - Hillco Fastener Warehouse. I used Hillco cat. no. AVO9688 Grade 8 studs that are 2.25" in length with 3/8"-16 course threads. However, if you're a purist and going for true factory OEM, you would need to use bolts for several. Your most cost effective solution will probably be to scavenge parts from your local U-Pull-It yard.

Also check out the recent thread titled "Crush Washers?" for the stock cupped washers used to secure the manifolds to the head.

Good Luck!
Dan M.

 

I'm not looking for the studs / bolts to attach them to the head. I have the bolts for that.

I need the studs that attach the intake manifold to the exhaust manifold.

 

Hi -

Based on the studs removed from a 1966 Ford 300 I-6, the studs appear to be 3/8" diameter, 4-5/8" in total lenghth. One end has 1-inch worth of fine 24 threads and the other end has 3/4-inch worth of standard course 16 threads.

Hope this helps...

Dan M.

 

Can I assume these are the two studs that attached the intake manifold to the exhaust manifold (not to the head)?

If that is the case, it does indeed help!

Now if I can just find the size / pitch of the plug for the second vacuum 'hole' in the intake manifold so I can plug it. The vacuum tree goes into the first one. And they are different sizes. My original intake just has the one hole..

 

I got motivated to do some digging and found the studs. They had been bagged when the engine was disassembled but not put with the other parts. In any case, I found the 3 studs I was looking for as well as the carburetor mounting bolts.

I just need to plug that second hole and I'll be good to go. It looks to be a 1/2" but not sure of thread pitch or type yet.