1993 W150 Extra Cab 5.9L 360 Magnum w/NV4500 5-Speed (1 ton Dana 60 Axles)

So, I'm considering doing an engine swap this summer; and I'm stuck between two good options: swapping a more modern Hemi (most likely the 5.7) or a 12 valve Cummins. Granted, I love the simplicity (relative) of my 360 Magnum, but the gas mileage is killing me. (9-11.2 MPG depending on how much highway time I have) When it comes down to it, which would y'all recommend? I understand that the Hemi would be the simpler of the two swaps, as it would work with my existing fuel tank, and a few other systems. However., ignoring cost of the swap itself, what would the better option be?

 

if you want better fuel mileage the only way to go would be the cummins but the cost of diesel is much higher so there is a good likey hood you may not see any improvement in cost per mile. i also don't see you seeing much if any improvement switching to a 5.7hemi. i would say the newer trucks only get sightly better fuel mileage and it is usually due to the extra gears in the transmission.

 

The modern hemi's have MDS witch shut's off cylinders when cruising. It can be an issue because it can fail and you have to replace the lifters. You can have it deactivated with a tune. I would go with the hemi swap. You may want to see what the issue is with the magnum. You should get better mileage than that but it also depends on how you drive.

 

there is likely nothing wrong with the magnum engine. over 14,000 miles tracked my ramcharger averaged a whopping 12.5mpg with 18mpg being the best it ever got over that time and it is only 2wd, getting 9-11mpg out of a 4x4 brick on wheels is pretty good and i doubt it would improve with a hemi unless you swap transmission and is it really worth a engine/transmission swap to only possibly gain a couple mpg? there is a good likely hood the fuel mileage will stay the same.

 

Thank you all for the opinions, and yeah, at the end of the day my truck is essentially a brick getting thrown down a wind tunnel when I drive it. I figure there won't be many, if any real improvement to the MPG that I could do... but I appreciate y'alls input regardless. It will definitely require far more research into boh options before I settle on either, or decided to say f-it to fuel mileage entirely and put a stroker kit on the Magnum. Thank you @Crassywofie for your opinions, and remiding me that the transmission plays a major part in mpg... I may have forgotten that a tad. And @Moparite, if I do end up doing a swap, a tuning kit is something I would definitely have to consider.

 

Another option would be the 2008+ 4.7 Other than the valve seat issue it's not a bad motor. Smaller displacement and slightly less power than the 360. But i have seen people turbo charge them.

 

Moparite,

That's a great option that I hadn't considered. I'll have to add that to the spreadsheet of possibilities regarding swaps.