Eugene wrote: Take a timing light and check for spark during cranking on each cylinder. Check against the pointer and timing marks.
Vacuum guage check if it still doesn't start.
Take a break for a day or two. Then double check everything. Then double check again. You are over looking something simple.
The gasoline engine is one big air compressor. The vacuum guage check will tell you a lot about the engine.
Yup. Getting interesting.