3.9 Stroker

The only way to do an acceptable stroker crank would be to ax the split rod pin and go to a common rod journal. This would require a bit of balance and it may shake anyway. Ligfhtest rods and pistons will help but inherent unbalance of a 90 degree V6 is hard to over come hence the split pin of the stock crank.

If you have a good block with low core shift you may get a 0.60" over bore or just sleeve all 6 cylinders and get a HUGE over bore. So the 292 limit is not really true.

And why stop at a 4 inch crank stroke? A 0.040" over bore and a 4.180" stroke to the 3.9 block will get you a 307 CI V6. Keep the compression low enough to put a Supercharger/Turbo on it and now you are talking major torque and HP.

(Dreaming here) This was a 100% truck engine so if Ma Mopar had pulled it head out its backside and did a 3/4 340 you'd have a 255 Ci V6 or used the 3.58 stroke crank have close to 275 CI V6.
Then do a 0.030" over bore and put a 4.180" stroke in for a 326 CI V6. Bit why stop dreaming and just do a 3/4 440....... 330 CI.