From Callies..the magnum XL series....


340 Mopar
* Stroke Range of 2.600 to 4.250
* 2.100 - 2.000 - 1.8885 Rod Journal Diameters
* 2.500 Main Diameter
* Weight Range of 35 lb. to 47 lb.


so if the 4.25 is 47, a 4 inch should be even less that that somewhat...a big diff over almost 70 pounds

69 Dart GTS A4 Silver All steel, flat factory hood, 3360race weight
418 BPE factory replacement headed stroker, 565 lift solid cam
Best so far, low 10.30’s 1/4
1.41 best 60 foot
6.56 at 104.17