1997 Dodge Dakota Truck will not start, after changing Timi

Yes we are getting spark and fuel. When we were trying to crank it, it even backfired up that is when we stopped trying to turn it over.

Ok we took the truck to a repair shop to have the timing redone, the timing was inncorrect. Now they say that either a dead cylinder or a bent valve is the problem can this be correct? We had the valves and cylinders checked before we replaced the timing chain. The only thing that was not checked before we replaced the timing chain was the MAP sensor, can that cause this issue?

We had a compression test done before the timing chain was replaced. When we bring the truck home we are going to have another compression test done. We are going to see if it sounds the same as it did when we first started having problems. We went through a long list of things before the timing was said to be the problem. It started with losing power when we were on the turnpike trying to go up a small hill, it would lose a lot of power and sound like it was backfiring it also had a rattle (this happened after we changed the spark plugs) then we changed the wires and distributor cap still had the problem. Then we changed the tbs sensor and still had the problem. We had the catalystic converter changed about a year and a half ago and this really sounded the same so we had that checked and that was still good. Then we had someone tell us that it sounded as though a cylinder was bad then we took it in and had the compression check done and they said it was low but in the ok range and it was the timing chain and you know the rest. I think we are now back to where we started. After we do another compression check if it comes back ok what should we do.