Big block blower housing on small block car

[streetk14]

I was considering adding a/c to my '68 small block Camaro, but decided it really wasn't needed. I plan to stick with the stock heater system for now but the problem is, I hate where the heater core/hoses come out of the firewall on my car. It is really tight with tall valve covers. I had seen that factory big block cars use a different core and position the hoses further to the passenger side for more clearance. Seemed like an easy solution, so I bought a repro big block case, heater core and core seals today. I just mocked it up, and found that the big block case does not cover up the holes where the small block core exited the firewall. What's the deal? The box came with a neoprene type seal, but I'm not sure what it's for. Could it be to block those holes? I'm not sure if the openings weren't cut from the factory on the original big block cars. If this is the case, I guess I would have to get them filled. I was hoping this was going to be a simple, bolt in deal. Anybody done this swap? Any ideas?
-Andy

[streetk14]

Ok, I found some info on this over at Camaros.net. All non-A/C caes had those holes in the firewall. There is a gasket that seals them off on big block cars. Now I just have to find some.
-Andy

[jannes_z-28]

I had the same problem on mine. There is a sealkit for the heater unit from Soff-Seal (I think that's the name) it includes all seals and gaskets for the flap doors inside the unit and also the piece that blocks the SB holes.

You will find it much cleaner with the BB setup.


Jan

[Kenova]

For the holes in my Nova, I just used a piece of sheet metal and some sealer. It may not be correct, but it works.
Ken

[dhardison]

For the holes in my Nova, I just used a piece of sheet metal and some sealer. It may not be correct, but it works.
Ken

Same here, I just put a small piece of sheet metal on the inside firewall held in place by sealer, then painted the exposed portion black. It's behind the passenger's side head, so unless you really look it can't be seen.

As Ken said, not correct, but functional.

[Rick Giles]

A friend of mine has an original 67 big block Camaro and it does have the same holes that the small block does in the firewall with some type of gasket material covering it. I just checked because I'm converting my 67 from small block to big block.