dodge at4 dating

Here's one for all the Dodge experts. A mate of mine has bought a Dodge AT4 with a slant six in it and we are having trouble dating it .
Chassis no AT4 135 3680
Eng no AT 20409.
Any help would be greatly appreciated.
Cheers Hardshar.

the chassis number will help .. also if its the original engine they usually have a date on the block

The number on the slant six block is under the rocker cover, drivers side front.
It will have stamped the engine size (225) then a build date.
My chassis number is almost the same At4 329 3680.
From what I can find the 3680 stands for the paint code of the chassis.
The rest...
Australian truck, series 4
3 Tonne
129 Inch wheelbase.

So what you'd friend has is a
1 Tonne 135 inch wheelbase truck.

Thanks for the info guys. We are still searching for info to date it. It is definatley not a i tonner as it has dual rear wheels. The agg weight still visable states 5 t 12 cwt.
Happy newyear to all.
Cheers Hardshar.

g'day all i can't agree with tonym if only because if all those chassis number details mean something pertaining to the build....it leaves nothing for a consecutive, down the production line, chassis number!!

...unless those numbers quoted are a chassis rail assembly part number and the real chassis number is elsewhere...

the workshop or owners manual usually quote where to find the chassis number.

but as usual idstbc.....cheers

I think there's something wrong with Hardshars original numbers. Tony's info is correct, with the "AT4", the first number representing the tons capacity, and the last two numbers representing the wheelbase.

However, I don't recall off the top of my head, the Dodges having a 135" WB. I recall 114", 129" and 133" .. but not 135".
I'd like to see a good close-up pic of those numbers to see if the forum members get a different opinion on what the numbers actually do say, and if there's agreement with Hardshars number ID.

but surely they can't have the same chassis number of 3680 ???...it all still doesn't add up

oh and by the way.... the old tried and true method of dating a vehicle can be had by checking the dots on the old armourplate safety glass with A being one (as in 1961) and on through the letters.

this works OK if the vehicle is still quite original but the whole thing can be chucked out the window if it's had a major rebuild etc etc

Hi Onetrack and Detective, Thanks for that input guys. I've been away for a week so i think i will have to go and have a look at the numbers for myself, i'll also check the glass.
Cheers Hardshar.

My Guess:
AT4= Australian truck series 4
1= 1971
353= 3tonand 153" wheelbase
680= production line number made

Gee I forget all about that truck. Mate mucked around with it for a while then all of a sudden sold it back to the guy he brought it off. Would have brought it myself if I had known. No idea where it is now.
Thanks anyway guys.
Cheers kevin