Alan do you think the reduction in journal overlap would make a big difference in strength. I recently saw photos of a forged 440 crank that was offset ground to 3.85 and used bbc rods and the journals were left with a fillet, maybe some one who has done it can chim in. I'm trying to build a motor with parts I have on the shelf, one of those being some h beam rods with bbc journals.
We've all been there, if it's a relatively mild I doubt you'll have a problem. BBC ran a cast crank with a 4" stroke. Whether it's worth the $$$ and effort, that's entirely up to you.
You might get lucky and someone who has done it will chime in, but I don't imagine it's been done often.
Best of luck
