AT4 and D5N trucks

We have just purchased two dodge trucks. One is a 1966 and the other is a 1974. I am wanting to know the difference between an AT4 and a D5N. Is it the front and year?

There are a few differences depending on the model, on the larger ones, the AT4 has a tapered chassis, and the D5N a parrallel chassis is one difference. Door handles and dash as well.

OH - The AT4 was built from 1962 to 1971 and featured 4 horizontal 5

D5N supposedly has different springs as well .. also different dash board(gauges) pretty much the hemi 245 is mostly found in the smaller D5Ns where the AT4 had the leaning tower of power (the slant 6cyl) also chrysler introduced electronic ign around 74-75? for their range of petrol engines not to mention the introduction of the detroit/GM V6 diesel engine option

Sorry Kenny, GM 6V53 came out in the AT4's, the last of them anyway.

D5N supposedly has different springs as well .. also different dash board(gauges) pretty much the hemi 245 is mostly found in the smaller D5Ns where the AT4 had the leaning tower of power (the slant 6cyl) also chrysler introduced electronic ign around 74-75? for their range of petrol engines not to mention the introduction of the detroit/GM V6 diesel engine option

Here's a couple of AT4 brosure's, I think Interstater has the D5N brosure.

Early larger D5N's got the tapered AT4 chassis rails along with the Cummings and also the push button door handles and then the last of the AT4's got the hemi 6 and detroit. Any D5N with wide front axle or flush door handles is a later truck. The smaller trucks used the same chassis/springs all the way through but early in the D5N they went to a different spring set up. Also the early Detroit trucks have the bonnet scoop and then the later ones don't seam to. I have not seen a detroit truck with the wide axle/flush door handles and bonnet scoop.

HTM, the bonnet scoop only ever hid where they had cut the bonnet and bent it up a bit where the air cleaner goes, a mate of mine in Bundy has one like that, and the motor in his sits about 2" further forward than mine as well, his is the narrow axle. The ones without the scoop must have the motor mounted a little bit lower in the chassis. Mine has the cab and gaurds raised 35mm to give it clearence under the bonnet.

Thats it and would make this truck a later one, wide axle flush door handles and no scoop.