[HO455]

Personally I would be shipping them back. I see no good reason let a vendor off the hook for something as simple as brake line fitting sizes. The only way vendors stop selling products that don't work is if we stop letting them. OK. I'm getting off my soap box now.

On your rear hose what style of Tee do you have? My understanding is that the 71-72's have a different style than the earlier ones. First photo is of a later style hose which uses 1/4" fittings at the axle Tee. The second photo is of the hose mounting plate on the later axle. (It also shows my PO's use of an early hose with a late axle) The earlier hose Tee has 3/16" fittings and no bolt hole. This information comes from me replacing the lines on my 67 Burban. The PO had swapped a five lug axle under it. (3rd photo shows correct hose installed). Both hoses have 1/4" fittings on the frame side.

I don't know about what the front hoses on a 70 might look like, but my 67 had 3/16" fittings on the lines with an adapter to 1/4" for the hose. I don't know if it was this way from the factory but it had definitely been that way for a long time when I took it apart to replace the lines. (4th photo). The PO had swapped the front to a five lug disc set up. hope this helps with your issue.

I also know the coil spring hoses are longer than leaf spring hoses.