Q: crank but no start

If you had the distributor out, which I believe is necessary for changing the manifold on that engine, you may not have it installed correctly. The gear is designed such that it can go in any number of positions so it’s up to the mechanic to see that the rotor shaft is in the correct position when it all goes together. You will need to take out the number one sparkplug and have a helper put his finger on the hole so he can feel the compression as you turn the engine by hand. When the number one cylinder is at the top of it’s compression stroke, you can check to be sure the rotor is pointing toward the number one wire and re-set it correctly if it is not. If you decide you need help with this, you can contact Your Mechanic. They can send a technician to your home or office to check out your starting issue and let you know what it will take to solve it.