What is the cam bearing problem?
I've had to scrape(with a bearing knife) more than one BB Mopar cam bearing to get the bearing I.D. correct for the cams to slide in properly, it is a problem with the factory machining them not big enough I.D.
I would say that 2 out of 10 blocks will need that, you can have the cam bore honed out also to make the bearings fit in them also.
I now install #5 cam bearing first and trial fit the cam and go from there if it fits and rotates
I don't like having to scrape a new bearing but you do what you need to do to make them, I'm sure that is one of the reason the cam bearings are so soft

I use a wheel cyl hone to clean up the bearings.. clean it alot.. use on the ones
that give you a problem.. I also have a cam that has cutter slots in it if I need it

I believe you can run a 55mm cam in those. A call to someone like Ray Barton can confirm/deny this. The cam won't be made from a $2 cast iron chinese cam core so it will cost a lot more money, but you figured that. But it will also be better. I don't believe you want roller bearings.

I have done everything with this block, this was the third time it has wipped out cam bearings.
This last time I installed Durabond coated bearings and then measured each cam journal bearing and then the cam. I then cut each cam jounal to give it 0.003" clearance. It turned real nice and I thought I had it finally fixed, NOPE!!!

When you say it wiped out the bearings, just some clarifying questions: 1) what does the failure look like ? Camshaft Bearing Diagnosis 2) is it on all journals or is it a repeated failure on just one?

I would suggest contacting someone like Best Machine,,Hughes Engine or other Mopar savy shops and see what tooling they have /use and their opinions on your issues.
Obviously something is wrong.
Not a typical failure in my opinion.

Well I can tell you this, it is a very typical failure, I have been racing Big Block Mopars for 35 years and when you start pushing the limit of a stock block there are tons of issues. Cam bearing failure is probably the #1 thing wrong with B/RB stock blocks.

Been racing and around Mopars for over 50 years, I can’t remember the last time I saw a cam bearing failure.
Super Stock, Modifed Production, Stockers, even fuel cars.

All using commercially available bearings, with nothing special being done to the bearings or cam.