BBC crank issues

I'm running a 555 BBC with a new century 10.2 deck aluminum block, callies pro magnum crank grp aluminum rods BMF 385 cyl. Heads 14/71 huh retro blower 50% od . I recently spun #2 main bearing , oh and I was running .0035-.004" main bearing clearance and .003" rod bearing clearance and running brad penn 60wt oil , everything looked great except for the no 2-3-4 main bearings, even the rods looked good, the crank Maged ok but is bent ( .010" run out on 2-3 main) first time I've had any bearing issues. What would be a good crank upgrade? I'm not running a crank support and don't really have room without a lot of modifications, any input would be appreciated, thanks!

 

It sounds to me that your bearing clearance is too tight. I would open them up to .0045 to .005. I do run an internal bearing crank support and a Bryant crank and V bearings, not M and 60W oil. No issues with my hemi
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Crank support.

 

Ya might look at oil volume too....I had a KB Olds a few years back that did not return oil to the pan very well....there was a restriction at the base of the return holes where they met the head deck and gasket...had to run uphill and then to the valley....we ran 10 quarts and blued the crank if we went much past 1/8 mile...a few more quarts probably woulda fixed the issue...I sold the engine with a brand new crank and also included a deeper dragster pan....so the next guy didn't have oiling issues...
The New Century and KB Olds blocks are very similar....but I think my issue was with the head combo and not the block....

 

What type of maintenance program are you on......as in when was the last time you looked at your bearings before this happened?

 

I'd check the clutch to make sure its balanced, straight and not wore. I would bend main caps and eat 2, 3 & 4 mains until I realized the clutch issues. I thought my clutches were fine until I started measuring with dial indicator and calipers.