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GMC Jim · 06-26-2003, 04:44 AM

'71 Chev. Service manual has the following specs for 307 V-8 w/ manual trans.:---Centrifigal advance-- (degrees @ RPM) 0 @ 800; 2 @ 1200; 12 and 24 @ 4300. Vacuum advance:-- ) degress @ 8" vac and 20 degrees @ 17" vac. Dwell setting :--31 to 34 degrees. Timing @ idle 4 degrees before top dead center @ 600 RPM (vacuum advance hose disconnected and plugged).
Another GM service manual ( #SD-100 1971-80 Tune Up Specifications ) shows a dwell angle of 29-31 degrees.... The total advance ( cent. & vac.) should be 26 to 34 degrees @ 2000 RPM.

06-26-2003, 04:44 AM	#3
GMC Jim Senior Member Join Date: Dec 2002 Location: Portland, Oregon Posts: 901	'71 Chev. Service manual has the following specs for 307 V-8 w/ manual trans.:---Centrifigal advance-- (degrees @ RPM) 0 @ 800; 2 @ 1200; 12 and 24 @ 4300. Vacuum advance:-- ) degress @ 8" vac and 20 degrees @ 17" vac. Dwell setting :--31 to 34 degrees. Timing @ idle 4 degrees before top dead center @ 600 RPM (vacuum advance hose disconnected and plugged). Another GM service manual ( #SD-100 1971-80 Tune Up Specifications ) shows a dwell angle of 29-31 degrees.... The total advance ( cent. & vac.) should be 26 to 34 degrees @ 2000 RPM. __________________ '71 GMC;fleetside;PB/PS/AC/CC/402 Eng./Custom Paint/110,000act miles/3 fuel tanks(52gal).