The CJ/SCJ had 73.5cc's
The CJ/SCJ heads feature 2.25 intake, 1.75 exhaust valves.
Screw in studs. Bottle-necked non adjustable 3/8" top/7/16 bottom studs for the early CJ and the adjustable 7/16 for the SCJ.
Guide plates (for 5/16" pr
Spring seats (cups?) and machined/hardened steel retainers.
The intake ports on the CJ/SCJ where of course large 2.86 x 2.12 with 2.24 x 1.32 ports for the exhaust.
The P.I. heads are very close to the CJ/SCJ.
With the exception of the ports being cast smaller at the port openings. 2.20" x 1.93" intake with 2.06" x 1.31" exhaust
Their intake valves being reduced to 2.19 dia.
Their cc's being upped to 88 to 90 or so.
They have the same screw in studs guide plates and spring cups as the CJ/SCJ features.
I think, in many ways the P.I. heads have better valve bowl castings and from what i have seen the P.I.s are far better for the street than the CJ/SC heads.