SBC timing

[oborowsk]

Just had my 86 Chevy C10 (305) rebuilt. After fixing a "no spark" problem, I have spark now but engine won't start. It is now backfiring out of the carb once in a while but doesn't run. Verified timing again by aligning TOC with mark on damper and making sure cylinder #1 is at TOC. Resinserted dizzy to make sure it points in the direction of cylinder #1 (aligns with #1 on dizzy cap). Hooked up spark plug wires according from firing order (my dizzy has a hold down ring that has them labeled). Unfortunately, I didn't verify that the new timing gear was aligned correctly before I installed the engine. Could that be the problem? How can I verify that it is correct without removing waterpump etc. again? If I take the valve covers off, can I check the valve position? For example, cylinder #1 at TOC, both valves should be closed (since it should be firing). Next, turn the engine 1/4? 1/2? turn and check if valves on cylinder XX are closed?
All the electrical stuff is hooked up but some of the vacuum line are not hooked up. Should the engine at least start without any vacuum lines connected? Do I need to plug any of them for it to start? Can the ECM prevent the engine from starting? Disconnect the ECM? Another thing, I hooked up a timing light and I don't see the marks line up but that could be because there is something wrong with the timing light. The light fires just can't see the marks align. Going to try to hook it up to different cylinders and see if it lines up. Any help is appreciated.