Be aware there are a few "1 year only" items about the car. I don't remember for sure, I believe later doors interchange, but that the window regulators are actually different. The rear bumper is only year with the reverse lights in the bumper, the tail light buckets are a bit smaller than 68-9. Of course no side reflectors or markers. The headlights are mounted slightly narrower, IE you cannot put a 68-9 grille on one without relocating the headlight mountings.
68 is first year of dash VIN, but neither 67 nor 8 are "numbers matching" as the body numbers are not partial vin, rather, they are an internal factory number. You can justify the body numbers to the vin if you have the build sheet and certicard I believe.
69 is first year of "matchiing numbers" AKA it does have partial vin on the body and engine, don't know about transmission.
If you do not have a service manual, run over to
MyMopar.com and dance around. I believe you can download both the factory manual and the parts manual