You have your truck timed an it will not start still what are you doing wrong I have an 85 shevy silverado pickup?

If an engine has proper compression, fuel/air delivered in the right ratio and the ignition spark is delivered at the right time when the engine is turned by the starter, the engine HAS to run... no choice.

Go back to basics. If you've worked on something recently and the engine ran BEFORE you worked on it, be suspicious of what has changed. It could be as simple as connecting the plug wires wrong.