1970 Overlander Frame vs 1976

[fullahotair]

I am in the middle of a body off resto on my 1970 Overlander. I've cruising through the posts here and noted that a few of the newer frames have extra frame support members than my 1970 frame. I was wondering if anyone knew why they were added to later models and if it would be wise to add them to mine. See attached pics!

My frame is the first pic....it doesn't have the extra braces that run front to back between the frame rails...

Thanks
Nate

[Lumatic]

This is just a guess. I think in 1970 Airstream was owned by Beatrice Foods. I have heard they made the frames lighter to save weight and money. An Overlander had a pretty good extension past the rear axle. I would think this causes a cantelever force which can add to rear end separation. 1970 Airstreams did not have a grey water tank. I know my black tank on my 71 was small. 2 tanks would add extra weight on the rear end, adding to the cantelever force. I don't know the specifics on 76 but these may be factors in the extra framing.

[fullahotair]

Thanks for the reply. I think i might add a piece of channel down the center...or perhaps two to replicate the later frames. I don't see the downside to doing so.

Thanks
Nate

[sgschwend]

Look at the space in the front too. Do you really want that large span in front that the floor will need to bridge over? Might be well worth changing the span to support the plywood better.

[fullahotair]

Does anyone know if Airstream used angle iron or c channel for the pieces that run down the middle?

I have both angle and c channel...debating on which one i'll use..

Thanks
Nate

[tjoneillMO]

I believe the members in my 23' 1976 are rectangular tube. This is a slightly stiffer section. May be different in a longer frame though. Either channel or angle would be good for floor stiffener though.