The alternator is without enough power, unsure of what is needed or what shortcuts to take.
The ignition is not fused.
Any smallblock Chevy engine will physically "fit" into a 85 Impala
cut all the hoses and wires and hook a chain to it and rip it out.
1985 Chevrolet impala
www.installdr.comthey have wiring harness diagrams for all makes
5 X 4.75 (120.7) Bolt Pattern.....
Look on the drivers side hidden in the frame ur going to need two wrenches.
If it has overdrive it is most likely a 700R4 transmission, if it doesn't,it is most likely a 350 turbo.
Stereo MCs was created in 1985.
Go to this site they almost every auto factory wiring diagram for free. www.the12volt.com
you can check your fuel pressure! check the timing, maybe even your crankshaft and or camshaft sensor. maybe weak fuel pump
The fuse box is located upunder the driverside dash open the door then look right under the steering wheel and there it is!!