I had a friend who was NUTS for all type of italian cars. He had a Fiat Dino, Ferrari Daytona Coupe, , a '63 250GT and the most pristine 124 Spyder I've ever seen -
He passed away from cancer a year ago and the family sold all his cars. I was hoping to pick-up the 124, but it was the only car the family kept.
IIRC, the Fiat Twin Cam is an interference engine, not because of the valves, but because possibility of the crank hitting the aux. shaft which is arguably worse because it causes a full engine teardown to correct instead of usually just a top-end with a valve interference engine.
Instead of pushing the car in gear (you'll literally have a ton of momentum built-up to damage anything if the timing has shifted), I'd take a socket and breaker bar to the crank pulley instead.
But, I have to caution you, if you think the timing may have slipped, even a possibility, the best thing to do would be to pull the timing cover and re-check the timing marks on the cam sprockets - that's the safest thing to do anyway.
