V6 HEI Timing

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85 Fleetside

Junior Member
Joined
Jan 13, 2020
Posts
4
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4
Location
Indiana
First Name
Scott
Truck Year
1985
Truck Model
C10
Engine Size
4.3
85 C10, 4.3L V6, 3sp manual, 350K miles, one owner. Curious what the centrifugal advance and vacuum advance should be on a stock V6 HEI distributor with ESC. My GM factory manual does not give specifics on this. The base timing matches the emission label which says 0 degrees with the vacuum advance line disconnected. Vacuum advance is 2 deg with 5" applied and seems to max out at 8 degrees with 10-15" (applied with a hand vacuum pump). With the vacuum line connected I am getting about 22 degrees BTDC at 2500 RPM. Does all of this sound reasonable? The truck starts easy and runs pretty good but does seem sluggish at times.
 

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