Which M20's come with "short skirt" I pistons?

[Vin-barrett]

Being pretty new to E30's this may be a noobish question.
I have an M20B25 longblock on the stand.
Before I start taking it apart and hoping for the best , is there an engine serial number break I can look for or something? Is there maybe a particular year or car that come with one or the other (short skirt/long skirt)?

Thanks for the help

[MR 325]

Some people will say it is dependent on year but I really don't think so.

I've torn down and been around MANY torn down M20 engines and I've only seen one or two with short skirt pistons. I do remember one of them was a late model engine, possibly 1990.

[Vin-barrett]

Thanks Mr

I will assume the short ones are not in the motor and plan accordingly.
Appreciate the quick response

[jlevie]

Per the IPB two different pistons were used in M20B25 engines. The change over to the "weight improved" pistons occurs in 6/88.

[whodwho]

For replacements they are listed for that early but I believe factory installed was later ~91