Dodge ID plate

[WesTheWinnebago]

Hey all, wondering if you can decipher what rear end and gearing etc from the dodge ID plate?  I have 74 Brave we are re-doing and looking to do a diesel swap so i'd like to know the rear end specs.  I think it's a RM300 chassis...

[Rickf1985]

I don't think you will get the rear end info from the vin, I just looked at the VIN decoder and there was no mention of rear end gearing but, there should be a tag on the rear cover with the numbers on it and if all else fails you can jack it up and turn the shaft and count the rotation of the tires. Just about all of them had 4:56 gears which is a bit steep for  diesel. Unless you have an overdrive transmission.

[DaveVA78Chieftain]

Information of that nature is in the Dodge MH Service manual.  The RM300 used a Spicer 60HD 7500lb (Dualies) axel with either 4.10 or 4.88 gearing.  There was a 2 wheelbases available (104" & 125").  I suspect the 125" base had the 4.88 gearing with a 11,000lb weight rating.

[Rickf1985]

Ok, So I was close. I split the difference. W%  4.88, WOW! There should still be a tag attached to one of the diff cover bolts.
This is why I usually defer to Dave on the older Dodge stuff, He is the Dodge guy.

[WesTheWinnebago]

Thx for the replies guys...I went out and checked the tag and it is 4.56 gears.