I am transplanting my 4.6L crank and pistons into a 4.0 engine from the junkyard. Extinct said that I could re-use my main bearings, but that was with only based off of two photos. I am posting more photos to further show the condition of the bearings. Can these still be re-used, or should I get new ones? Note that one of the bearings in the cap is pretty scratched up, and one of them in the block has a nick that is circled. Will moving bearings to the new block cause any problems with the seating?

 

I would replace them, they are a bit worn and you are already in a place to do them

 

Agreed. You're in that far, replace them.

 

Agree with the previous 2, but if budget is really a problem, the bearings look fine to reuse. Just remember that gas will be over $80 per tank, by comparison, to go 300 miles or so. So, $80 worth of bearings is not a huge input in the long term.

 

That top layer is only .013mm thick typically (ref: https://ozparts.eu/4B603H-20) and you have not even worn through it, waste of money in my opinion.

 

Will replacing them increase the chances of the crank grabbing on and spinning a bearing?

 

Def not

 

It is common knowledge within the Automotive field, that you Do not reuse bearings, ever. The reasons are many, and extremely well documented if folks care to look.