1979 Amc Spirit hatchback daily driver

We got this for a daily driver, it had a new valve job, and rebuilt transmission, and ran fine, we did all new brakes, master, calipers, wheel cyl. pads, flex hoses,etc. added aftermarket stereo, without cutting dash, (still have stock am radio). It ran fine for a couple years, about 11,000 miles, then started dieseling, running on after turning off. then one time it would not start afterward. Our mechanic friend looked at it and said the timing belt had jumped.I'm told a 304 V8 will fit in these nicely, and thought of doing that, but a year has gone by, and have lost interest in the project idea. It's a fun little car even with the 4 cylinder. It has no major rust I can find, just surface rust, body is pretty straight, a few small dings, interior fairly good for it's age, plastic trim inside is brittle and cracks fairly easy though. front rugs are fair, but rugs in hatch are bad. glass is all good, windows work, all electric worked ok, it has ac but not working. Door and hatch locks are worn and take some wiggling. tires are fair. It had regular service while we were driving it. The hood latch Knob is broken but works with the aid of pliers. And recently I found that the drivers outer door handle stopped working to open the door, inside one still works, so I believe the linkage retainer clip is broken. Paint is faded and has surface rust but no pitting. headliner fabric was gone when we got the car. that's all I can think of, but feel free to ask questions, will answer asap.