The C Chanel frame height on the Ram Cab/Chassis frames start out very tall at over a foot (about 300mm) then taper to the smaller size referenced (I think he said 190mm). They hold that until they terminate at the aft end. They are about 3" wide at the top and bottom of each channel (75mm).
Rear end differences change year to year. From what I remember when I bought mine the 3500 was closer to the 4500 internally, but I believe they used the same sized carrier externally. We're talking ring/pinion/bearings/etc. The 4500 of course has the dual wheel setup for more capacity. Not sure what the difference was between the 4500/5500 other than springs at the time. It's probably hard to know for sure unless you get info year by year though as I believe this is a bit of a moving target. The info I had at the time may have been extrapolated from another year and totally wrong depending upon the source so take that with a grain of salt.
Its funny. Expedition Journal did a podcast with Dave Harrington and I believe he mentioned that up to 80% GVW was the sweet spot, but also said to subtract out due to tire height over stock, etc. Then when on to say that he'd done things with his Rams that were well beyond their design specs. when he was at a point in life where he didn't know better or funds necessitated it (paraphrasing here). In short, they have a lot of head room, but expect more headaches the harder you push them past their designed envelope. There is something to be said for how hard the operator pushes things too. I try to drive with mechanical sympathy so as to preserve the asset. This is not what we often see on the road though.
I think track width is going to be your biggest issue if going with the 4500 and above depending upon the trails you hit in Europe. You can get the track between front and read pretty darn close with super singles. The front offsets toward the inside, the rear toward the outside and this puts them near in line with each other (unless I got it backwards but you get the idea). The other thing to consider with super singles as the tires used which are appropriate for off-road use are speed limited to around 70mph. Wouldn't get on the Autobahn and wring its neck. The truck will do it, but the tires won't keep up...for long.
Rear end differences change year to year. From what I remember when I bought mine the 3500 was closer to the 4500 internally, but I believe they used the same sized carrier externally. We're talking ring/pinion/bearings/etc. The 4500 of course has the dual wheel setup for more capacity. Not sure what the difference was between the 4500/5500 other than springs at the time. It's probably hard to know for sure unless you get info year by year though as I believe this is a bit of a moving target. The info I had at the time may have been extrapolated from another year and totally wrong depending upon the source so take that with a grain of salt.
Its funny. Expedition Journal did a podcast with Dave Harrington and I believe he mentioned that up to 80% GVW was the sweet spot, but also said to subtract out due to tire height over stock, etc. Then when on to say that he'd done things with his Rams that were well beyond their design specs. when he was at a point in life where he didn't know better or funds necessitated it (paraphrasing here). In short, they have a lot of head room, but expect more headaches the harder you push them past their designed envelope. There is something to be said for how hard the operator pushes things too. I try to drive with mechanical sympathy so as to preserve the asset. This is not what we often see on the road though.
I think track width is going to be your biggest issue if going with the 4500 and above depending upon the trails you hit in Europe. You can get the track between front and read pretty darn close with super singles. The front offsets toward the inside, the rear toward the outside and this puts them near in line with each other (unless I got it backwards but you get the idea). The other thing to consider with super singles as the tires used which are appropriate for off-road use are speed limited to around 70mph. Wouldn't get on the Autobahn and wring its neck. The truck will do it, but the tires won't keep up...for long.
