New dizzy stiff to rotate

I just picked up a rebuilt dizzy from AZ, had old and new on the bench comparing that they are the same part, and noticed the old dizzy spins very freely, while the rebuilt does not. It isn't like it takes a wrench to turn it, but I feel resistance. Should it be stiff to turn since it just got rebuilt? Or is that a sign that something isn't right?

Thanks.

Sigh . . . on to the next issue

The rotational stiffness seems to be normal, as I compared to others at AZ.

So I thought I'm good to go, went to stick the dizzy in the hole, but didn't get very far. The first round part of the housing of the dizzy starts into the hole in the block, but binds up after about 1/4". It's not that it's hitting the oil pump drive shaft, as I can try the orig dizzy, and it drops in further before it hits the shaft. I went back to AZ and got another dizzy, and same exact issue. Before I take a file to try and size down the housing, is there any known reason for this, like slightly diff models of dizzy out there? As far as I can tell the rebuilt dizzy is the right part, as all measurements are the same, and the casted ford part number on the dizzy housing is the same. I've measured the round part of the housing that's binding with a rule, and it looks the same, so it's probably only a few thousandths off.

Or, is there someplace I can take (send) my orig to be rebuilt? I don't really wanna mess with it.

Thanks