Not trying to bust into some else's thread, but does that spec sheet mean a 1985 D150 with a factory 360 could have only come with a 3.54 or 3.90 rear gear and an Auto 4spd transmission? Just curious because I have no clue what rear gear or transmission my 85 D150 has.

 

I see 4.10, and 4.56 for the 360 as well. I don't see a listing for a manual though??? That seems odd, I was sure they actually came with manuals, didn't they????

 

You are correct, very odd sheet. I guess my best bet is to test speed / rpms and count the shifts.

 

no. that sheet only applies to newer trucks probably 91 and newer since based on gears/transmission and engines engines listed. 3.9 wasn't used till 88. overdrive wasn't available till 89 and i don't know if 89 or 90 was the last gear for 3.23 gears since with overdrive you do not need 3.23 gears to bring engine rpm's down at highway speeds. so based on this no this does not apply to your truck

 

so actually it doesn't match my 85 W250 either I suppose, It sure came close. According to the sheet dodge did not make all kinds of different load capacities in different trucks like it is now. It looks like if you bought a dodge truck in those days you were getting a high performance truck no matter what in my opinion

 

If you're lucky, the tag will still be on the differential cover. It may be pretty nasty but if it says 35, you have a 3.55 for example. A way to find out if the tag is gone, they are usually removed or rust off by now, is to jack the truck up, release the parking brake and put it in neutral. Rotate one wheel by hand and count how many turns to make the drive shaft rotate once. This will get you close even though it's a bit of a jack leg solution. The only sure way though, is to drop the rear cover and count the teeth on the ring gear. At the age of your truck, are you sure you have the original rear end? I went through two rear ends and the third was going out when I got rid of my '84. Then again, it was just shy of 400K when I sent it down the road.

 

So no first gen rams came with factory OD until 89?