There must be a difference between the 67 and 68 heater installation. Here's mine.
The heater core is intalled in the box, not on the firewall.
You can see where the factory allowed for the bent tubes to clear on the firewall here. The blower box on the firewall has to come off to allow the tubes to pass. This means, hood and fender off!
1968 Firebird, 350 4V, TH350 with trans-go, 69 slap shifter, 8.5 inch 10 bolt 3.42 posi
