Your timing is way out. You need to realign your wirings going into your distributor. You need to get the engine at TDC on the compression stroke on cylinder #8. The rotor at this position is pointing #8 plug wire. Make sure the #8 wire going into distributor is positioned to engage that position on the distributor. Use the firing order and proper direction to plug in the rest of the wires.
Engine Test Stand Playlist: https://www.youtube.com/playlist?list=PLwoxyUwptUcdqEb-o2ArqyiUaHW0G_C88 restoring my 1968 Firebird 400 HO convertible (Firedawg) 1965 Pontiac Catalina Safari Wagon 389 TriPower (Catwagon) 1999 JD AWS LX Lawn tractor 17hp (my daily driver) 2006 Sequoia 2017 Murano (wife's car) 202? Electric car 203? 68 Firebird /w electric engine 2007 Bayliner 175 runabout /w 3.0L Mercuiser__________________________________________________________
