Gen 2 Mark 8 motor help

[Dr.Apex]

I found a mark8 motor with 98k on it that comes with the ecu for $500. I have never bought a motor from someone so I need your help.
The motor is on a stand right now. How do I go about making sure I don't buy a really big paper weight?

My plan is to drop it into my 98 but I'm unsure of what kinds of problems or extras I will need for the swap. So, any help/advice or places to find informative reading on it would be greatly appreciated.
This is a no rush situation since the guy has 3 of them, 2 of which are gen 1's.
I'm assuming that the gen 2 is better than the gen 1 but if you guys have anything to say about that....please do.
Thanks

[LTDmasta GT]

make sure intake is the same. Gen 2s have an intake similar to the cobra intake where the Gen 1s have the tubular style. exhaust manifolds are different for Mustang so make sure you have your old manifolds.

be 100% sure its out of a Mark 8 because these engines were also available in the FWD Continental, but the bellhousing bolt pattern is different.

[Dr.Apex]

Originally Posted by LTDmasta GT

make sure intake is the same. Gen 2s have an intake similar to the cobra intake where the Gen 1s have the tubular style. exhaust manifolds are different for Mustang so make sure you have your old manifolds.

be 100% sure its out of a Mark 8 because these engines were also available in the FWD Continental, but the bellhousing bolt pattern is different.

How do I go about making sure the motor is from a mark8? Are there serial numbers or anything on it to verify?

Also, will my 5-speed tranny bolt right up, or will I need to get an adapter?