I'm wondering what is the best choice in rod and main bearings for a street engine that is driven daily, sometimes driven hard, rarely raced. This engine has a factory forged crank and about 9.7:1CR if that makes a difference. I have credit at a store that offers only Clevite, so that's mainly what I'd like info on. But other opinions appreciated also. Clevite part #s MS 909 H MS 909 P CB 663 H CB 663 HX CB 663 P Much thanks

Its been a little bit since ive dealt with bearings, but from what i can recall (i use Clevite bearings, too):

The first thing i did when selecting a bearing was inspect every single bearing for polishing and smearing, sometimes some discoloration. basically what im looking for are signs of any oil starvation on the rods. Bearings run with different levels of eccentricity. Eccentricity really boils down to how much oil is allowed between the bearing and the crank. whether it be rod or main bearings. For the normal builder "standard SBC" bearings do fine. If youre like me and want every part to be matched to your purpose, that includes the bearings. While eccentricity may seem like one of those "more is better" issues, it really isnt, depending on application. If you are running a high rpm motor, the higher level of eccentricity is key. More oil flow = better running temps and less chance of oil starvation. However, the high-eccentricity bearings, at lower RPM can cause for oil pressure drops. So in a daily driver, high eccentricity isnt always the best thing. I run the Clevite deltawall-P rod bearings. I feel they give me the perfect balance of high rpm features and fatigue resistance 9they have hard backing versus the normal P-series). They have more of a medium eccentricity. Which i like for my motor that is a DD, but sees high rpm duties.

On the main bearings i run the H series. they have the same medium eccentricity which i prefer for MY engine. You really only need to run the H-series if your crank has enlarged fillets. Remember, these were desisigned for NASCAR. For your application, you could probably get away with running the P-series.

One key factor to keep in mind, though. As you increase the amount of oil that circulates around the crankshaft, you need to run a higher volume pump. That isnt a problem if you already have one, but if you dont, and you plan on increasing the bearing clearance, you might want to consider it.

RB can probably elaborate on oil pumps and bearing spacing.

But like i said, i cant give any clear cut suggestions without knowing the intended RPM range. But as a start, i will suggest the P-series for both rod and mains. H wouldnt hurt though as long as yo uhave adequate oil supply

i'd look at FM bearings, clevites are trash and their quality control is non existent

Clevite bearings are made by Dana http://www.clevite.com/
Federal Mogul is Federal Mogul http://www.federal-mogul.com/cda/homepage/index

As long as you mentioned it...
I was noticing that the running surface on Clevite bearings isn't nearly as hard as Fed Moguls.

This will be for a motor that's pretty much built to ZZ4 specs, probably with a slightly larger cam and I don't plan on really beating it that hard, but I know I'll be taking it to the track at least a few times.

Thanks for the replies, I'll look into some FM bearings then.

little harder to find and cost a little more but childs&albert make very good parts