Increased Wear on bearings front to back?

Deeply considering adding and oil balance line to my 350. After 40,000 very rough high rpm miles and street stoplight to stoplight shenannigans, the bearings took a beating. I think it was probably only a thousand miles more of that from spinning a bearing. #7 was coming apart and there was plenty of material in the pan.
After rolling in new bearings, I noticed the front bearings which get oiled first looked almost new. I'm considering adding an oil balance line. Will this alleviate this issue?

 

Smaller oil feed passages on 2, 3, 4 and 5 mains. This thread is on a 455 but 350 has the same issue. Also talks about the balance line and a link at the end to more oil mods.

Main Bearing Feed Passage Oil Restrictions | V8buick.com

 

350, 455 the oil mods need to be done doesn't matter which motor. 50 lbs at 3 grand is what you need to have. 10+ at idle 15-20 better

 

Start out with a freshly ground or polished, smooth finish on all main & rod crank journals. You shouldn't feel anything using your fingernail profilometer.

 

What main bearings are you running,half groove?

 

That's what I got.

 

Yes. 4481m010.

 

I did when I originally built this engine..002 clearance on the dot.

 

This is what I do

 

Nice. Pic of flexplate side?

 

The crank must have had more scoring than you thought in the beginning since you had decent oil pressure.

 

Please note you can not home polish a cast crank properly, period!

There is a specific way the crank needs to be spun and that is based on how it was spun if it was ever ground undersized .

 

When I got the engine it had a few ridges. .010 wasn't necessary but I wanted to see if it would net me better more stable oil pressure than slapping bearings on a standard worn crank. It seamed to.

 

Yep.

Grinding opposite to engine rotation then polish the same direction of operating rotation.

The action of any work will create "fuzz/burrs" in the direction of the work, so the reverse will "strip/remove" these burrs, and as each step in the process of grinding, finishing and polishing in opposing directions will properly reduce them to insignificant levels. Going in only one direction for all steps, just "lays the burrs down" sort of like greasing a "cow lick" on a young boys hair. It will lay down for while, but later, it sticks up and ruins the family portrait!

 

This is how I ran my line. Plus my machinist did all the oil mods. When spinning a motor twice the speed it was designed for there’s no such thing as overkill.

 

Steve, you paint your heads or leave natural?

 

Nice and compact, I dig it. Beautiful setup as well.

 

7 and 8 rod bearings were coming apart, and I'm surprised it wasn't knocking. A few hundred more miles of that highway rpm and it probably would've been curtains.

I'm hoping the balance line will add more volume to those last few bearings to get oiled. I know there will be a few psi pressure drop overall, but if it'll help those rear bearings out it seems like a worth while upgrade.

 

Left natural. Was looking to give them a clear coat, but couldn’t find anything that I feel wouldn’t yellow around the exhaust ports.