Advice? Yes, I know they both suck and everything is old tech. Goal: (finally) get it running--cheap and reliable: -original to this car 307, sitting out of it for over 25 years. Complete unknown. -'86 t/a (parts car) 305. I got it running yesterday. It had not run in maybe 20 years, but obviously basics still work. It smokes but runs pretty smooth considering. RockAuto: 305 kit (no machining) ~$400. 307 kit ~$200. The 305 kit is Sealed Power components and the 307 is off-brand/unknown. I've got to check the parts lists. I figured the 305 would be cheaper--newer and way more of them around? My wife rightly points out, why put money into another motor you don't want to keep? Actually she asked why even keep the 307 when I explained it was original but not actually valuable. (I also have a 350 core that I planned to build for the longer term, higher $ version.)I could put the ignition, intake, and fuel parts from the 305 on the 307 since I now know they work.