The 2nd Generation Grand Am were built in several different combinations.
Although the base model build was a V6 with a manual transmission, I have only heard of 1.
The base build in my opinion was a Pontiac 301 with a 200 metric transmission. (78-79)
The majority of the 78’s had a 2 barrel carb. and the 79’s had the 4 barrel car predominantly.
1980 could only be purchased with the 4 barrel carb.
High back buckets seats with center console can be found in 2 and 4 door cars. If it was a console delete car, it would have a column shift. (manual shift excluded)
Grand Am rear seat back have 2 extra tuck lines across the back. They have 2 extra chords that are hog ringed to create the extra detail of the seat. Lemans and Grand Lemans won’t have this
Door panels: What I think I’ve seen, is that the 78-79 Grand Am and the 78-79 Lemans share the same interior door panels. Lemans will not have the door pull strap. The 78 Grand Lemans uses the 79 Grand Am door panels and the 79 Grand Lemans uses the 78 Grand Am door panels.
I’ve seen AM/FM, AM/FM/8 track and AM/FM/CB radio options. Power antenna was option, but standard with the CB…I think.
Front speakers are in the dash and could be duel (1 in each corner) or single placed in the center of the dash.
There may be duel rear speakers, single rear speakers or no rear speakers under the rear package shelf. Some later G Body cars had the Concert Sound speakers placed towards the front of the lower door panels.
Grand Lemans hoods have a chrome strip down the center. There are holes in the hood due to the mounting studs on the hood.
Grand Lemans has the same side body belt molding as the Grand Am