[RJGeister]

According to the resto guide I received from Chevrolet, it is based on GVW.

4400 lbs was a G78-15 bias ply tire.

5400 lbs was a H78-15 bias ply tire or a 6.50-16 bias ply tire.

Any tire shop should have a tire book to convert the old tire sizes to the metric tire sizes.

Hope this helps.

Rich