Re: old 350 block
Welcome to Team Camaro!
Sounds like the distributor may be installed 180 out. Pull the valve cover and verify that both valves are closed when the rotor is pointing to #1 cylinder.
'69 Camaro - 429 SBC Dart Iron Eagle 9.325" block, Crower crank, Crower 6" billet rods, Ross pistons (10:1), Total Seal rings, AFR 245 heads, T&D steel body shaft rockers, Cloyes Timing set, custom ground 4-7 swap solid roller 274/286 @ .050" with .704" lift, Dart single plane, Holley Dominator EFI on E85, Injector Dynamics ID2000 Injectors, Stef's #1705R oil pan, F2 Procharger, Lemons 2" primary 4" collector, ATI 9" blower converter