here's some details of cams J,R,B, so you can measure.
I got them from this thread.
http://www.kzrider.com/forum/2-engine/590239-stock-j-model-cam-options
1982 KZ1100-A2, rated as 92 hp:
Intake (12044-1027):
Duration: 270 - Lift: Not exactly sure, but a little less than the 81 GPz.
Exhaust:
Duration: 270 - Lift: Not exactly sure, but a little less than the 81 GPz.
Used on:
KZ1000-K1 (LTD) (1981)
KZ1000-K2 (LTD) (1982)
KZ1000-M1 (CSR) (1981)
KZ1000-M2 (CSR) (1982)
KZ1000-P1 to P24 (Police 1000) (1982 - 2005)
KZ1100-A1 (Shaft) (1981)
KZ1100-A2 (Shaft) (1982)
KZ1100-A3 (Shaft) (1983)
KZ1100-D1 (Spectre) (1982)
KZ1100-D2 (Spectre) (1983)
KZ1100-L1 (LTD Shaft) (1983)
ZN1100-B1 (LTD Shaft) (1984)
ZN1100-B2 (LTD Shaft) (1985)
1981 KZ1100-B1 Gpz, rated as 102 hp:
Intake (12044-1031):
Duration: 280 - Lift: 8,4 mm (.330") - Open: 35 BTDC - Close: 65 ABDC
Exhaust (12044-1036):
Duration: 280 - Lift 8,8 mm (.346") - Open: 68 BBDC - Close: 32 ATDC
Used on:
KZ1000-J1 (1981)
KZ1000-J2 (1982)
KZ1000-J3 (1983)
KZ1000-R1 (Eddie Lawson Replica) (1982)
KZ1100-B1 (GPz) (1981)
1982 KZ1100-B2 GPz, rated as 109 hp:
Intake (12044-1037):
Duration: 288 - Lift: 8,8 mm (.346") - Open: 34 BTDC - Close 74 ABDC
Exhaust (12044-1037):
Duration: 288 - Lift: 8,8 mm (.346") - Open 72 BBDC - Close 36 ATDC
Used on:
KZ1000-R2 (Eddie Lawson Replica) (1983)
KZ1100-B2 (GPz) (1982)
1983/84 ZX1100-A1/A2 GPz, rated as 120 hp:
Intake (12044-1057):
Duration: 300 - Lift: 9,6 mm (.375")
Exhaust (12044-1057):
Duration: 300 - Lift: 9,6 mm (.375")
Used on:
ZX1100-A1 (GPz) (1983)
ZX1100-A2 (GPz) (1984)