I found scratches on the bearing surface that is deep enough to be felt. Should the bearing still be usable or am I going to need to buy a new bearing set?

 

What does the crank look like ? How did the scratches get there ?
Ok, I know this sounds crazy........ find a dime that is 1982 or older........rub it over the scratches til it smoothes out the feel of the imperfections. It might be good enough to use.
........Just my two cents worth

 

It's a new bearing, it got damaged before installation.

 

Lightly/gently polish out any raised scratches with crocus cloth. Install the bearing then measure the clearance, if the clearance is within spec I believe it will be good. Sure, I'd prefer a new one but think about how small the scratches are in comparison to the oil groove in the center.

 

Would 1000 grit sandpaper work instead of crocus cloth

 

Why are you even asking this question? Yeah, it may be fine, but life will really suck if you get the whole engine together and it isn't. Did whatever made those impact marks also push the bearing out of shape? It will never be easier to replace it than right now. Did the bearing show up that way - in which case get it replaced.

 

How much is it to replace? $10?

What would a failed engine cost you?

The way I look at it, calculate the worst case scenario and ask yourself "Do you feel lucky Punk?"

 

If I could find a new single bearing I'd replace it without even thinking. All I can find is $50+ sets and hardly any bi metal.

 

Keep in mind that those small pits become like microscopic reservoirs where dirt will gather and stay eventually leading to premature wear. Replace it.

 

I have a saying about any kind of bearing. "When in doubt, throw it out." Johnny Cochran would be proud of me.

 

I was just about to ask how the pits could actually affect bearing performance cause I couldn't think of how they'd stop the bearing from doing its job.

 

$50? No brainer to change it.

How much did you invest in your rebuild?

 

Does anyone know where to find bi-metal main bearings for a 350? Those were Sealed Power but I can't find them anymore.

 

Standard or undersize ?

 

Dunno if it is too late, but Rock Auto sent me an update yesterday with close-out purchases for "67 Cutlass" containing main bearing sets from Mahle. $58 and change. I know it is still in the $50 plus range, but not bad for tri-metal. You might try an engine building shop to see if they have any single bearing pairs left over from previous builds.

 

I noticed Mahle/Clevite used to have a full groove front main, only available in standard and $50 more, should be on clearance. Why is the .010" undersize $20 more than the other sizes?

 

Because it's probably the biggest seller.. I doubt if many sbo's that get torn down don't go back together without a crank regrind. And you either suck it up or have the crank ground to the cheapest size.

Roger.