Ok I know there are differences between the exhaust manifolds between gen2-3 something like the 3 having an extra bolt/stud through it?
Where is it located?
When I puled my gen2 manifold off I noticed a spare bolt hole on the left hand side top would this be it and if so would it be possible to bolt the gen3 manifold up?
Gen I and Gen II will work i believe with the Gen II having the extra studs and same for Gen II onto a 3SFE but someone is pulling your mates leg about the manifold being for a Gen III.
Bolt holes aren't the issue it's the port spacing that is different. Lay the gaskets over each other and you'll see there's no way a Gen II and III could be swapped