Does king make a +.001 bearing? I couldn't find any and std hp's are at .0045 on my mains when I checked today. Picked up some coated clevites a few minutes ago.

I went through all of the bearing questions a year ago when I built my shortblock - traded a lot of emails with they guys in Mahle-Clevite's tech support department. For the most part, in marine engines the general consensus is still .0025 - .0028 on rods and around .0030 on the mains - most also like to run a little more clearance in that rear main as well, maybe around .0035. I am not going to begin to claim to be an expert, but I did communicate with several highly respected builders around these forums, and there are some who are starting to move away from large clearances with high volume oil pumps and heavy weight oils and more in the direction of tighter clearances with lower oil pressures and lighter weight synthetic oils. That's not to say that your engine is not going to live if you run the wider clearances, but the thinking is that it might not really be necessary to put so much pressure on the distributor drive gears and use up extra HP to run 50 weight oil at 90 PSI. I'm sure there are going to be many differing opinions on this (much like camshafts).

Have you measured the main bearing bores? Is the issue here, or has the crank been polished to produce the extra clearance?

The crank is 2.748, so the my guess is the bore is a little loose. Ill have to measure the bore tomorrow and make sure there is sufficient crush.

AFR 315 Heads
victor Jr
950HP
10.5 to 1
Dyno Headers
715HP at 6000
697#/ft
91 Octane California

296/300 237/241 206/208 154/151 96/75 .363/.335 103/111

Are you using a bore gauge and a mic to get your measurements? I'm pretty sure king makes a +1

I'm with you on that everyone has there preferences on clearances and oil. I've seen .006 clearance on some big hp twin turbo stuff with an extra thrust bearing in the front of the block. The way I look at it is as the hp goes up so do the clearances if you want it to live.

Yes dial bore gauge, checked it several times.

cstraub thank you that's the kind of reply I was looking for.

Look at that cam a little closer.

Main thing that should stick out is the 107LSA. (103/111 centerlines = 107LSA)

Would you put that in an I/O Offshore boat ? I think not.