87 7MGTE vs 89 7MGTE

[Virusx86]

I recently bought an 87 N/A Auto that had been swapped into a Turbo 5Spd and was wondering if there was an easy way to identify which gen got swapped in? I imagine something on the ECU? I know I should search for this but I can't seem to phrase the query to get what I want

 

[supra90turbo]

Pull the oil pan. On the crank it will be stamped "6M" or "7M"
If it says "6M", it's an earlier 7MGTE. Fewer counterweights on the crank make it a less smooth running engine, but it has a higher rev limit stock (6750rpm)
If it says "7M", it's the later design.
It's got more counterweights on the crank, making it a smoother engine. Due to the increased rotating mass, the factory RPM limit was decreased to 6250.

They're both just as good as one another. No point in checking just for that.