I've thought about building a 4.0 stroke B/RB stroker motor but haven't built one yet , maybe next year I've built more than one 3.91 stroke B and Rb motors and 4.150, 4.250, 4.320 and several 4.375 strokers with stock Mopar rod jourmnal sizes, never again using the 2.375 rod journal diameter by choice What made you decide to use that stroke? I'm thinking that combination will like RPM
i Cab, years ago i built a 475 cube rb motor out of a stock crank cut to 2.10 sbc size at 4.0 inch, using a BME 396 aluminum custom rod. It worked great for what it was. The rod was 7.10 long, which fit some stroker pistons i had from a motor that broke a crank. The 2.10 bearings held up well, and the second owner got a lot of life out of it
, maybe next year 
I've built more than one 3.91 stroke B and Rb motors and 4.150, 4.250, 4.320 and several 4.375 strokers with stock Mopar rod jourmnal sizes, never again using the 2.375 rod journal diameter by choice 
