Finishing up after installing new water pump. Timing marks line up on crank and Camshaft. Is it possible, though, to have the two 180 degrees out? And if so will it just not start or will it cause catastrophic damage?

 

The cam is the critical part as long as the crank is at top dead center #1 and the cam is lined up for tdc at #1 then all should be good. It is a very good rule of thumb to rotate the engine by hand atleast 2 full rotations and feel for anything touching in the engine. Its easier if the plugs are out cause you wont feel the compression. I always do that when I change belts on my hondas and it has saved me atleast once.

 

make sure the piston wasnt at TDC before you put your cam in time. Always time the cam first so you dont bend valves. If all the marks line up you are good to go