Thread: Question- Mystery Plug

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Got my block back from the machine shop. Started re-assembling it. Back by rear main seal I noticed something wierd in one of the holes. I was a some sort of plug that was in the hole sideways. I can't recall if it is supposed to be there or not. (I know it doesn't go in sideways if it does though). It was in the passage that goes between the oil filter to the main. There was another plug below it that looked good. I'm just not sure if there is suppose to be one above the plug that is deep down in there.

Anyone know? Here's some pictures to show what I'm talking about.

picture of plug

oil drilling? Just a total guess.. But this should move your post up to where someone should notice it.

ok.... so what is the story with the plug? Is it supposed to be there installed correctly ..flush with the deck or is it not supposed to be there at all?

when I got the motor the cam had wiped two lobes...justmore info

anybody?

J K , I can't believe no one here can answer this?!?!?!?

Here's what I would do tho. Get an air chuck that seals the hole. Blow 10PSI air into it. 10PSI won't blow out any other plugs. Then just trace out the passage.

Does the air come out the crankshaft bearing feed holes? Chances are that is an oil galley hole. Probably does need a plug (installed correctly) may need two if there are two holes in the area between the plugs.

I would also go to the local chevy dealer or speed shop and request all the plug deallys needed to fill that *(%%^(^$ hole next to the bearing journal. Then pump them for more info as to the point of the hole.

thanks guys, I appreciate it.

DUDE this is so important!!!!!! with out it your oil will not go through your oil filter and will bypass it completly!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!pop it out and put a new one in , if you look closly you will see a shoulder that it seals in drive it home till it stops and you will be in good shape- the machine shop should have poped this uot before thet hot tanked it ???????????

I'm still confused...... are we saying that there should be two plugs in the same hole? Because I have one plug in there that is driven about 1.5" deep. You can see the shoulder of it in the top picture. The other plug doesn't even fit tight. It just drops and hits bottom. Besides that it looks like if I installed it it would only direct flow from the oil pump to the rear main.

I checked the other bare 350 block I have and there is only the one that is about 1.5" deep, not a second one, closer to the deck.

NO, just one should be in the hole , try to get the one that is sidways out and trash it!!

yeah, that's what I figured. The one that was in there has been trashed. It didn't even seem like it was the right size. It wasn't even in there snug. I'm wondering if it got up in there while the block was being shifted around the shop.

So, I'm cool with the plug that's in there down about 1-1.5" , right?

Thanks all.