Help decoding an engine number
 

I looked at a motor for sale today, it was purportedly a '70T 2.2 liter. The Zenith carbs were there, but it had a red shroud, not yellow as I thought it would be. The engine number was 6539077 so it should mean "6" for 6 cylinders, "5" I can't figure out because my book only shows 1,2,or3 for T,E, or S The "3" should mean it's a '73 motor, and the "9077" is it's consecutive production number. So the question is what's the "5" signify?

Thanks, Mike Quigley

On Pg 51 of "Original Porsche 911" The engine number is listed w/ 1973 911T Sporto, under engine 911/67, under gearbox 905/21, with engine #'s 6539001 - 6539197. Maybe this helps...

Jimmy, So since this is a manual trans car, it likely received this motor as a transplant for a defunct original 2.2 I presume.

Thanks for your help.

Mike Quigley