I'm looking to purchase a non X coded 69 SS 396 Camaro,and looking at the heater box it seems strange to me,I've never seen one like it.The heater core pipes exit from the center of the box,(like it should on a big block car), but it seems like the heater core pipes are spread wider(up and down) apart than usual,and the pipes don't have that collar type grommet around them,but where the heater core pipes would exit if it was a small block are blocked as if it were original.It almost seems like somebody drilled out a small block heater box and relocated the heater core to the center of the box.The location of the heater core exit holes are not even in the right location as all the big block heater boxes I've seen pictures of. Is it possible that someone,at sometime was trying to fake this b/b car, or did they come like this? The firewall looks uniformly weathered as this car is in original unrestored condition. Any help would be appreciated. Dom.

Check the caulk color should be a darker grey

I modified my SB blower box to BB just as you described. I used a BB heater core, measured, and drilled two holes. Opened them up a bit and I used the correct adapter (collar)from NPD. It looks like a stock BB blower box when finished. I can't speak about what you were looking at, but when done correctly, it looks stock.

Codi; Sounds exactly like this car, But I'd like to know how you blocked off the S/B holes in the firewall, this car looks original.

You would have to weld up the holes and do body work over the holes. That is what I did to mine.

Pro; Is that to say that a B/B Camaro has those holes closed off from factory? In a permanent fashion, or are they plugs that you can punch out?

The smallblock holes are there on my 68 factory BB car. If I remember correctly there was just a pad that seals them from the inside, It comes with a replacement in a new gasket kit.(Car was 10 years when I bought it, someone else could have been into the heater box by then)
HG

Deep.......a foam pad is what seals the old SB holes in the firewall. The pad comes in a seal kit and it just adheres to the inside of the firewall, coverning the SB holes. Nothing much to it. This is all then covered by the firewall insulation pad, under the dash.

Thanks to HG,Codi and the rest of you. This information has opened my eyes to this "B/B" Camaro.What a great site.