Early vs. Late 7R cases?

[Phoenix]

I'm searching for a 7R case to use as a basis for building a 2.7 RS spec motor. Can someone tell me if the following case number is the 2.4 7R case or the later 2.7 7R case? I can never tell the difference.

901.101.102.7R


Many thanks guys!!

[jluetjen]

Oliver;
I believe that that number is the casting number. My understanding is that the only difference between an "early" 7R case (from a 2.4 liter motor) and a "late" 7R case (from a 2.7 liter motor) is the dimension of the spigots which is just a machining change. The thing is that once you've machined the spigots of a 2.4 case to fit 2.7 cylinders, the world has lost a 2.4 case forever.

[CliffBrown]

Oliver

Check the serial number. The 1973.5 2.4T used the 7R case. The serial number should indicate 613XXXX for an early case.