Why do they need Chamfering? I recently bought a Source crank expecting that to need bearing chamfering but it didn't, all the Clevite bearings fitted perfect with 0.0025 clearence on all journals. Couldn't ask for better.

Maybe I'm missing something but why would you order bearing before crank....just because they say it's so don't mean it is..or am I thinking wrong order bearing get crank go from there ..I would think check block order crank then get bearing and machine to spec..am I wrong in my thinking..

i want to make sure the bearings especially the thrust bearing fit the aluminum caps while i have the block at the shop. i have been told sometimes the thrust bearing doesn't properly fit these caps. really doesn't matter either way as it sounds like i will have to have the crank machined for clearance anyway.

well, thats good to hear. i talked to source today and they told me the clevite ms876p main would have to be chamfered. they sell the chamfered bearing for something crazy like $179 a set. ouch!

When I was chamfering bearings for an early Source crank it was only the rod bearings that needed attention. The new crank I bought was fitted up with HN bearings & they fitted up fine with no clearencing issues.

I have the MS 876P bearings and the info says they are narrow for clearance on all aftermarket cranks.
Mick

Why are people still making the Mopar size journals...???

IMO no reason NOT to go 4.25", with a 6.535" (BBC +.500") you can use the same 1.32" CH piston they make for any 451 B low deck 6.76" rod combo, everybody makes that piston. a 4.25" with 2.200 journals has BETTER block clearance than a 4.15" stroke with the B/RB mopar journals.

FWIW....the 4.15" stroke came about because it mathematically allowed any RB owner to bump to 493 cubes by boring to 4.342" reusing his 6.76" rods and using an off-the-shelf 400B piston.

yeah, hn. the n is for narrow. thats how king does it. would have bought the king mains but they dont offer a full groove.

i hope that is correct. my save me alittle

The 4.15 piston is only 468g though.

I just had Ohio crank take a 440 4.250 stroke crank and make me a 400 4.375 stroke with 2.2 rod journals. When it was all said and done I have around $700 in the crank. I started off with a new k1 crank

ohio crank will do what ever you want,i have a 4.500 stoke,chevy rod 2.20,,400 mains,knife edge,counter weights cut down,lighten,in a 400

Which type, steel or aluminum, H beam or I beam rods did you use in that motor? How much block grinding for rod clearances was needed with that stroke? I haven't ran a 4.375 stroke in a 400 yet, much less a 4.500 Thanks in adavnce for the answers

Are you using the Mahle pistons?

the mahles i would like to use are 512g. these are 1.350x4.375

If you plan on purchasing Mahles, price check a few sources. JEGS was $100 less than Summit when I ordered mine.

i found them for 607 . not sure if that price is still current.

BIG BLOCK MOPAR (B) / 383, 400 Flat Top
1.5, 1.5, 3.0mm File Fit Performance Ring Set included 72cc 80cc 84cc
499 4.375 4.150 6.760 1.120R 0.990 -8cc 467 12.4 11.4 11.0 4032 0.350 0.0041 0.0049 BBM120375F08
Compression Heights with "R" INCLUDE Oil Support Rails

These are what I was looking at...

i looked at those too. I was told may not be a good choice for a street/strip deal.