I recently had a chance to compare my BB heater box to a SB. I thought they were both the same and the only reason the BB box had a different part number was because of the hose cover or clips or heater core or the rubber hose hole cover. So, I tried putting the core from the BB in the SB box. It did not fit. After closer examination, I found the one thing that is different between the 2 type boxes. The BB welded in heater core plate is approximately 1/4 in. wider. I could probably make the SB work with a BB core, but I would have to modify, I.E. hammer, to make it fit. Below is what I found. I hope this helps someone ID their box in the future. Bottom box is the BB one.
Good info to know. Would you have measurements? I did not notice when I had mine out. Side by side would be noticeable.
Good job Bentley!
Scott
Bentley thank you for identifying that bb and sb heater boxes are not identical. I'd like to add a measurement from my 1967 SS 396 heater box. The flange is noticeably wider here than a sb heater box. Can anyone add a measurement from a sb box?
I found this out the hard way!😂 I always look for the little bead roll inside the big block box to identify them!