My g/f's sister has a 90 caravan with the 3.0 in it.
Is this an interference fit engine where the valves hit the pistons if the belt slips a tooth or two?

 

Usually you are ok if it only jumped a couple of teeth. But I believe that it will hit the valves if it is far enough off, the only way to find out is to replace the belt, you don't have to put the engine all the way back together to see if the valves are vent or not. Put the new belt on, get it all setup and start the engine while it is still sitting on a jack and see if it skips. This engine is hit or miss as far as bending valves, about 50/50 odds that it did.

 

If that's true, why can I rotate the cams and there is no loose rocker arms like you would expect with bent valves?
I have removed everything on the engine but the heads. The oil pan, front cover, timing belt, oil pump and pickup tube, spark plugs and cap and rotor. AND there is still a binding!! That leaves only two things left to check-the bearings and pistons. This engine is frustrating me.[sm=headbang.gif][sm=bomb.gif]

 

The 3 liter motor is a NON-interference motor. If you have binding with the motor torn down as you mention, then you have a bearing issue. Let me backtrack... If you are turning the cams and only the cams, there will be some "binding" due to the spring pressure on the rockers. They will not turn smoothly. If you spin the crank and have binding with the plugs in, you are going against cylinderpressure. Pull the plugs.

For 3 liter info http://www.geocities.com/phatfoto/EEK6G72.html I wrote this as a sort of FAQ, and I do have new info to add. But for now, this is the most complete info base for the 3 liter...

Roger