[Rock Hornbuckle]

OK Marine! Let's do it by the numbers...assuming the new plugs are correct.
You remember what the Corps taught us about assuming!
1. check battery voltage
2. turn key on
3. check voltage to the coil
4. check output of the coil
5. check pionts gapped properly
6. plugs gapped properly
7. check spark at plugs
8. check engine timing for #1 cylinder at TDC
9. gas valve open
10. start engine

This may sound crazy to you, but I would check the sides of the plugs to be sure they are clean. When I was a teenager I would prank my buddies by using a lead pencil and drawing a line down the side of their plugs, causing them much frustration when their cars wouldn't start.