What front axle did your Bump Side High Boy come with from the factory? Did it have the 3,300 pound (Dana 44-6F) or the 3,500 pound (Dana 44-6FHD)?

I had a '71 with the HD and my brother had a '70 with the LD.

 

You should ask this over in the dentside forum too...

I was under the impression the 3.3M axle was last used on the highboys in '73 and the 3.5M axle became standard from '74 onward, but a few guys claim otherwise.

 

That's what my parts book shows. I have seen very few Dent Sides with the 3.3M axle. I haven't seen to many Bump Sides with the HD axle either. I've only seen one High Boy Slick in person and one on the internet with the 3.5M axle. I've only been roamin' the earth for 16 years though. Some of you folks have seen a lot more.

 

X2 on the parts book.

That's been my experience as well, i don't see many bump highboys but the ones i do see mostly have the 3.3M axle...

I've seen a ton of dent highboys and almost all have the 3.5M axle...

To the best of my knowledge the 3.3M axle was standard equipment on the 67-73 highboys, and the 3.5M axle was an optional upgrade (it seems very few bumps got the 3.5M)

The 3.5M axle became standard equipment on the 74-77 highboys, and the 3.8M axle (low pinion D60) was an optional upgrade.

 

My 70 CC has the HD, and my 76 CC has the LP 60.

 

From what I can make of the parts book, for '74 & '75, the 3.5M was the only option. It looks to me like the 3.8M became optional in '76. I could be wrong though.

 

My first was a brand new 74 and it had the light duty hubs. I had a 69 with the heavy duty. I think it kind of depended on the GVW as to which front axle you got. IIRC my 74 was around 6400. I could spot the different from a long way off because the light dutys sagged a little in the rear and the heavy dutys the rear was a little higher than the front. That's just general impressions and I'm sure those with the exact information will choose to correct me. Factory literature for any given year will show the GVW ratings available, more than just 2 so I suppose some in the middle ranges could have came with either front, but I am just speculating.

 

After a second look that's the way i'm reading it too, though it is a bit ambiguous.

Why the 3.8M would be an option on the 76/77 highboy but not the 73/75 doesn't make any sense.

If you notice, the parts book doesn't even list the 3.8M for the 76/77 crewcabs...

73/75 CC's got the closed knuckle/drum brake 3.8M....76/77 CC's got the open knuckle/disc brake 3.8M

That's why i don't put 100% faith in the MPC (parts book) when i know otherwise from real world experience.

 

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