Posted by Ken Dunnington [172.68.3.51] on Sunday, November 16, 2025 at 13:50:01 :
In Reply to: Repower 1/2 ton closed cab wc12 posted by DDD [104.23.245.36] on Saturday, November 15, 2025 at 07:36:55 :
The leaning tower of power in my '67 D100 with an NP435, 3.55 r/p, 235/75R15 tires has been a very nice combo for this truck.
It pushes it 75 mph on the flat highway at 5K+ feet elevation, up to 9K feet with a load doing 45-55 mph, gets 17 mpg and, of course, provides the joy of a straight 6. Nothing fancy done to it, it's just the 2 bbl version from the factory(not original to this truck). I recall seeing a factory blow-thru turbo on one in a later Dodge M series ambulance. Lots of hop-up can be done if mo-power is desired.
It's old school Mopar but can be easily modernized with electronic ignition and EFI and one can source a later one if one wants to avoid the small extra maintenance time of the solid flat tappets.
Some of the late export flat fenders were equipped with it from the factory. I forget which ones.