Posted by Vaughn [172.69.134.19] on Friday, August 26, 2022 at 19:34:34 :
In Reply to: engine swaps posted by Todd Miller [172.70.206.75] on Friday, August 26, 2022 at 11:14:07 :
Good question:
The Cummins 4BT Long Block engine weight is approximately 750-800 pounds depending what it has on it. Dodge 230 Long Block engine is approximately 550-600 pounds. The 4BT torque is approximately 420lb-ft (4BTA) which doubles the engine torque of the 230.
Engine Support:
What to do about the additional engine weight – Some builders add additional spring leaves to the springs. I’ve lifted 200-300-pound boulders under my truck to move them around the yard as instructed by the wife to get a prettier yard look, and it handles it just fine.
Transmission:
Is changed out with whatever transmission will mount the engine and gear speed builder desires. It makes it an easier swap. Floor covers may need to be modified to accommodate the swapped transmission. If using the NP420 transmission and PTO, you’re turn the two gears, idler and reverse gears in the PTO resulting in more heat and drag, a reason to consider other transmission/PTO options as parts are more available.
Transfer Case:
The NP200 is strong enough to use, but it builds more heat at higher road speeds as it turns two gears, the intermediate and driven gear to the rear differential. A reason to consider other transfer case options, such as an NP205 which is a straight through to the rear differential when not in four-wheel drive.
Front/Rear Ends:
The front end is ok to use, it compares favorably to a Dana 60/70. The rear end is usually swapped out for a center differential from a late ¾ ton WC due to the long axle shaft on the driver’s side, it’s a weak point, however the stock differential can be used with care. Using a Dana 70 from a W300 in front is an easy bolt up to the springs, same perch distance. The Chevy Military M880 and other M8XX truck axles work well, track width of the FFPW is 64-3/4 and the M880 front is 65.26, rear is 64.0 inches, so they are very close to the PW track. There may be later Dodge axles close to the track as well. Parts and upgrades to the axles are easier to get.
Summary
You can use most of the stock units when converting and if you plan to build a daily driver, switching out units to improve fuel economy makes good sense. There is a downside to swaps, you can experience engine heating with the 4BT pulling grades, as reported on the forum, as well as V8’s, so that can be an issue that has to be solved, if possible once you make the conversion. Some builders stick strictly with Dodge parts and that’s fine, while others mix/match parts to get the desired build, and that’s fine as well.
Follow Ups: