What's the trick to installing the two-piece heater core housing and blower box? I tried installing the heater core housing first as the Camaro assembly manual appears to show but then you can't get the blower box in place without scraping off the 3M sealant rope.

The driver's side is the problem where the heater core pipes are close to two of the studs.

You have to be very careful not to hit those heater core pipes upon instalation.

Mount the h. core in the box and have someone on the engine side helping to guide the core in.

I can install the core into the housing and get the housing properly located to the firewall. The problem comes when I try to attach the fan box to the engine side of the firewall.

I'm beginning to think the fan box needs to be in place first but this is hard to accomplish with one adult and one five-year-old helper.