I recently put a 5.7 hemi together, never thought anything about it after doing tons of mopar engines... put the timing marks cam at 6 and crank at 12. When I was spinning it over, at 1st had a tight spot, but seemed fine. Put in the truck and it sputters and spins fast when I tried to fire it. Turns out I had the them both backwards. Lucked out and didn't bend a valve since it's interference engine.

Anyways, it happens!