SC's had different stock cam timings:
930/04 = 0.9 - 1.1 mm
930/07 or 930/16 = 1.4 - 1.7 mm
Your '81 would be 1.4 - 1.7 mm for stock cams, IMHO.
1.4 mm for a 964 profile was recommended to me by a few experts and I am very happy with that.
Re-time carefully going around three times.
You can actully see one chain sprocket through the sump opening with a light and mirror on the I-shaft on either side of the larger drive gear.
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1980 Carrerarized SC with SS 3.2, LSD & Extras. SOLD!
1995 seafoam-green 993 C2, LSD, Sport seats.
Abstract Darwin Ipso Facto: "Life is evolutionary random and has no meaning as evidenced by 7 Billion paranoid talking monkeys with super-inflated egos and matching vanity worshipping illusionary Gods and Saviors ".
