I have a blown head gasket , long story short the head I got in the mail is the U 8th digit when I have the V , looks exactly the same though ? but the autozone website says the U wont fit the V

 

Welcome to the forum

Both heads can bolt to the 3.0l block, "fitting" is not the issue at all

Look here: https://www.therangerstation.com/tec..._0-build.shtml

Scroll down just past 1/2 way and you will see the difference in the heads Cylinder cavity shape, one is 49cc(VIN U) the other 47cc(VIN V) volume
You don't want to use one of each on the same block
Doesn't matter which Pair you use, as long as both heads are U or both are V