There is no evaporator on that model.
you have to remove the fender
To remove the windshield trim on a 1968 Chevy Impala you will need a trim removal tool that has slides which can release the locking clips.
The first was a Norway teak style...I cannot find the maker. It was stolen in 1986. Carson replaced it 1986 to 1992, with a Ronson Rosewood table lighter from circa 1968
Remove inside door handle and window crank handle, remove inside door panel, remove vent window and channel assembly, remove window.
He died in hospital after a house fire on August the third, 1968. Luther had gone fishing the day before, had cleaned the fish and apparently fell asleep on the couch with a lit cigarette. (Referenced in the film "Walk the Line" when Cash takes a lit cigarette from the sleeping Luther's hand.)
The 350 engine was first used in the 1967Camaros, Novas, and Chevelles. It was 295hp. I believe it was used in all of the Chevy models the following year, 1968. The hp. increased each year til 1970, then started going back down again in 1971, due to lower compressions and emission control equipment.
Impact driver and lots of rust penetrant.
With a wrench..7-8 open end.
It is necessary to either remove the passenger side fender or inner wheel well to access the heater fan in a 68 camaro.
It's tight, but it just pulls off... With some effort.
If you can not find it online, by looking up 66 chevelle wiring diagram, then buy a chilton book for 64-75 chevelles, I have a 1964, and just finished a 1968 nut and bolt body orr restoration, and without the chilton manual, i would of been lost, with some things, you can get the manual at most automotive stores, walmart, ect.