Need help with 3.4 cam bearings

[evartsboy73]

I have a 1999 Chevy Venture with a broke camshaft. I have the motor all tore apart and on the stand I have the cam bearings out. There is a lip(For lack of better word) on the bearing journal holes inside the block. It is on both journals. Or whatever it is called. Where the bearing goes. I have included a pic of it. Is it suppose to be there? They both look the same like factory made. Maybe to stop the bearing from going all the way thru when installed.The van ran fine and the camshaft break was instant. Also there is like a wear groove where each bearing sits. This is like it would have took awhile to make the grooves or lips. Bearing were thin but not torn and chewed up and the cam could not have done the groove or whatever. Just really stumped on this. Can someone please reply with some advice. Will oversize bearings fit or what. Yeah the block needs cleaned. I have not attempted any kind of cleaning on it.

[SappySE107]

Shouldn't be a lip to keep the bearings from going through all the way. The bearing didn't spin in the bore?

[evartsboy73]

Yeah the 2 inside bearings did spin but they stayed in place and were thin. Not worn thru though. I looked at more last night and now I want to say it is suppose to look like it is. Just not sure. I looked at it more at a level view and not with cocked up a little on the stand. Do anyone know of pics floating around of the actual inside of the block of a 3400 or 3100? Please reply soon. Here is a few more pics. Cant really get good pics of what I am talking about. Maybe it is just the oil galley or valleys that I am paranoid about.

[SappySE107]

That is why the 2 inside journals look like that then. Block is junk, new bearings won't have enough press fit.

[evartsboy73]

Could a machine shop fix it where oversized bearings would be ok? Also I can get another block just with a bad heads or that is what I was told for $50. They say is was from a 1998 Lumina. Mine is a 1999 Chevy Venture. The blocks will be identical, Right? Also I already have new cam, bearings and lifters and timing chain and everything else and if the old cam is fine with good tight bearings then should I be good to go with just standard cam bearings? That is what I have. Thanks so much for your input and advice. Please reply soon.

[SappySE107]

Are there oversize OD bearings? You would have to measure the diameter to find what you need and buy 2 sets of cam bearings. If you can get another engine for 50, do that. You could use any 3400 block and put the outside parts on it to match what you have. The block itself is the same 96-05. I don't understand what the broken cam has to do with tight bearings.

[evartsboy73]

The bearings I have is standard. I am taking the block to the machine shop and he said he would look at it and could tell if it was fixable. I trust him, He has been in the business at least 40 years and still does it all him self and he stays swomped with business. I just am torn about getting the other block not knowing about the condition of its cam bearings. Can I measure myself? What do I need to measure the bearing bores?