Quick question on heads

[darush01]

I haven't posted in a few years so if this violates any newer rules I apologise. I rebuilt the too end on my 72 c20 and wound up with a broken rocker stud on one of the heads, I put the truck in storage and left it until now, I'd like to go get it and get it running so I can at least move it if I bring it home. That's the back story, the question is I have a set of heads for a 400 will they work on my 350, I know the bolt holes match, and if the will work what kind of difference am I looking at? Any help is appreciated

[bautino95]

Here's a funny story. When I bought my truck I drove it home something like 35 miles, then I continued to drive it as is for a little while more. I thought someone just put too big of a cam in it and it was a tired engine. Anyways when I tore it down to rebuild it I found several bent push rods and one completely broken. So long story short you can drive it although not recommended if its not that far to your house if your only down one cylinder. You could pull the valve cover and remove that push rod and rocker and so its not bashing around it there. then fix it right when you get home.

[darush01]

Ive got a trailer to get it home I'm just dead broke and I have the 400 heads sitting on a shelf so figured if there's not a good enough reason not to I'd use what I have.

[Steeveedee]

They will work if you want to use them. They have the steam holes drilled to match the holes in the block, which won't be used in your case, but that is no reason not to use them. They will work fine.

[Boog]

Seems like I remember the 400 heads need steam holes drilled in them.

[Duck 37]

Just sold a guy a set of after market aluminum heads for a 350 and he was going to put them on a 400. He said all he had to do was drill out the steam holes. Didn't know what that meant. Hope this might answer your queston.

[darush01]

Thanks everyone for your replies, I know my buddy took these heads off of a freshly rebuilt 400 and replaced them with 350 vortec heads and gave them to me I was just saving them because I'd already bought a set but since the set I bought were defective I guess I'll clean these up and use them, I just want to have my truck running so I can keep it from rotting away.

[68is4me]

Heads should work fine, the steams holes would get blocked by the head gaskets. Can you just repair the existing heads with out pulling them?

These are screw in studs made by mr gasket that you just drill and tap existing holes.

[darush01]

Originally Posted by 68is4me

Heads should work fine, the steams holes would get blocked by the head gaskets. Can you just repair the existing heads with out pulling them?

These are screw in studs made by mr gasket that you just drill and tap existing holes.

I don't know, I didn't know they made those, the existing stud was held in with a little pin

[AussieinNC]

Pinned studs are used when valve spring pressures are higher than normal and is a cheap attempt to stop the studs from pulling out of the head.

If one stud has snapped, there will be others close to doing same ....drilling the stud for a pin actually weakens it...

Suggest you have the spring pressures checked and free coil clearance checked for bind...

If it were my engine I would be getting a different set of heads...

[darush01]

Originally Posted by AussieinNC

Pinned studs are used when valve spring pressures are higher than normal and is a cheap attempt to stop the studs from pulling out of the head.

If one stud has snapped, there will be others close to doing same ....drilling the stud for a pin actually weakens it...

Suggest you have the spring pressures checked and free coil clearance checked for bind...

If it were my engine I would be getting a different set of heads...

I have another set , that's what this thread was to find out if the 400 heads I have would work on my 350

[nikwho]

I believe that they'll work. You would need to drill holes in 350 heads for steam holes. going the way that you are is fine. the head gaskets will block the steam holes off. Do you know the combustion chamber volume? stock pistons/bottom end? May want to compare combustion chamber sizes to know how the swap will effect your compression ratio.

Nik

[Steeveedee]

Originally Posted by AussieinNC

Pinned studs are used when valve spring pressures are higher than normal and is a cheap attempt to stop the studs from pulling out of the head.

If one stud has snapped, there will be others close to doing same ....drilling the stud for a pin actually weakens it...

Suggest you have the spring pressures checked and free coil clearance checked for bind...

If it were my engine I would be getting a different set of heads...

Yup. The 400 heads probably fit the bill, even if the studs are pressed in (?). Maybe those heads should be tapped for screw-in threads...

I've tapped heads for threaded rocker studs as a mechanic. Boring...er...threading.

[darush01]

It is a completely stock bottom end, I'm actually worried it won't hold up but for right now I'm willing to risk it, it will have no really strain on it j7st the occasional drive to the gas station for quite a while.