So here's where I'm at, I am about the modifiy the factory heater box to try and pick up some extra clearance for the exhaust pipe while maintaining the function of the unit. But first I wanted to see if anyone could see any obvious flaws in my plan.
I think that there is just enough room to fit the factory core sideways, parallel to the firewall instead of protruding out from the firewall.
Here are some pictures:
So remember this:
what i was thinking was to mount the core like this:
From another direction
Its a lot of cutting and splicing, but some 1/2" aluminum angle iron on the inside and some weatherstripping for support and sealing and a new sheet meet outer with about 1" of space along the height of the core for air flow may be enough. Which give me a couple of extra inches clearance, the blue tape line is close and the turbo manifolds are not installed, but i gives an idea:
Here's my real concern, IF (and its a big if) I can get the core to fit and the cleances right, How much additional resistance to flow will forcing the air to bend 90 degrees make? Will it likely be a problem to the function of the heater?