Uh oh......

[CJim7]

(amc 401) Directly under the intake manifold at the foremost part of the block, there are 2 large threaded holes that form a V. Can actually see right through the block where the oil pressure reg goes. anyhoo....are these supposed to be capped? I have some extra plugs in my parts box from the machineshop that fit them...but I cant remember if they were plugged or open.

Im betting they were plugged, but thought I better check first. :-|

[dwloop]

Yes, they are the front lifter galleries oil passages. They need to be closed with plugs, there are two in the rear as well...

Dave

[CJim7]

Thanks Dave, I suspected that.
Are you sure there are galleries towards the rear? This is directly under the intake manifold, and I see nothing at the rear. :-|

[AMX69PHATTY]

Other (2) plugs are on the back vertical surface of the block, one on eah side and slightly above of the Cam bearing hole freeze plug, where they would end up being just forward of the flexplate/flywheel. Also, there are (2) in the front face of the block. The one on the passenger side can NOT screw in too far or it could block the #1 cam bearing oil feed hole. So there are a total of (6) 3/8 oil galley pipe plugs, (2) front, (2) front top in valley, (2) rear. For reference the stock 3/8 pipe plugs have a square socket hole, not a hex socket hole. Not that it matters, was just mentioning it.

[CJim7]

Perfect! Thanks guys. :t:

fwiw and just for accuracy for anybody else seeing this, the two galley plugs under the valve cover are larger then 3/8...they're more of a 5/8 or 9/16.

Now that I think about it, I have all 6 of the used plugs in the parts box....the 4 (new ones) that are in the vertical face of the block are all there.....I wonder what they did with the 2 larger galley plugs they should have gotten with the rebuild kit. :-|

[Zoner]

fwiw and just for accuracy for anybody else seeing this, the two galley plugs under the valve cover are larger then 3/8...they're more of a 5/8 or 9/16

There are 6 of them total:
- 2 under the timing cover
- 2 astride the aft cam bearing plug
- 2 in the front of the lifter galley (over the front cam bearing)

They are .645->.665, which looks about like 3/8" NPT to me

Look up "National Pipe Thread" on Wikipedia for a size reference, and the reason why 3/8" actually measures this big...

Drive fitting is 5/16" square. I know this because I had to special order a pipe plug socket, and just took them out of my project engine core yesterday.

[CJim7]

Drive fitting is 5/16" square. I know this because I had to special order a pipe plug socket, and just took them out of my project engine core yesterday.
Yeah, I had a hell of a time finding the proper driver for that bastard. :roll:

[CJim7]

Also, there are (2) in the front face of the block. The one on the passenger side can NOT screw in too far or it could block the #1 cam bearing oil feed hole.
The used plugs they sent back included one that was shorter then the rest. I think i'll pull the new plug out and see if they used a short one or a longer one in there. The last thing I need is bearing oil feed problems on a new engine.
Do I need to use thread sealer on these things? Looks like they used teflon tape nearest I can tell... :idea:

[Zoner]

I'm no expert, but since the front 4 are inside the oiled area, probably not much point to seal them; a little weepage won't hurt.
The back 2 could dribble and make a mess if they don't seal just right (or make you think you have a rear main leak). If they're driven in enough, it should be minor to negligible.

Some say teflon tape shouldn't go near anything hydraulic. I'd guess it's probably OK if you're careful with it.

[CJim7]

Some say teflon tape shouldn't go near anything hydraulic. I'd guess it's probably OK if you're careful with it.
I read you loud and clear.