Question using NASCAR SB narrow rod bearing CB481HN?

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dibbons

dibbons

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Just spoke with my custom rod manufacturer who told me he machined the bearing tab slots differently in the upper and lower parts (rod and cap) of my connecting rods. The reason being the sample connecting rod bearing I sent him had the tab offset a little differently between the two halves. At least, that is what I understood from the conversation a few minutes ago.

Now that to me sounds extremely odd/strange/disconcerting. I hope he did not screw up the orientation of the rod bearings somehow. The reason for using this narrower NASCAR rod bearing (CB481HN) is to accommodate a crankshaft with full radius fillets. Anyone have experience with this Mopar small block connecting rod bearing and/or the full radius crankshafts? This is all new for me. The project I am working on is a de-stroked 340 to 305 by way of a 2.96" stroke crankshaft replacing the standard 3.31" crankshaft. Thank you.
 
Is the new crank a full radius crank? But regardless, if you sent a bearing sample, then your new rods should be machined to fit your bearings...I can't see a problem
 
It's basically a 340 with a 2.96" stroke, 6.298" connecting rods to compensate (6.123" are stock length), old school NOS TRW L2322F dome pistons which afford about 10.5 to 1 compression in this de-stroked version, close to factory manual custom hydraulic camshaft profile (276/284:221/227 @ .050 lobe lift .438/.456 lift with 114 LSA), with a stock '72 340 intake manifold, stock '72 340 thermoquad, and "O" open chamber heads with the 2.02" intake valves. Just trying something a little different.
 
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My Eagle cast stroker crank (Dont hate, Im not overpowering it) ) had full radius fillets and I had 2 choices: Buy the 'race' bearings that were more narrow and were 4X the price, or take a bearing knife and scrape the edges down of regular bearings to clear the fillets. I chose the latter because I had already bought them. I actually took a die grinder and zipped the corner off the outer edge and test fitted them. Worked fine with no binding. The Mopar cast cranks have a 90 (actually an undercut) at the journals.
 
There isn't room for two conventional bearings with a large radius (.125eg)
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fillet crank. The use of the feeler gauge is demonstrating the fact that the con rod is being held away by the (conventional width) bearing ridding up on the fillet
 
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