Harmonic Balancer/ Cover ?


MalibuRacing Junkie
Sep 18, 2006
West, MI
I bought a 6.3/4" harmonic Balancer cover #66517BK for the 84 L69 305 H/O. The problem is the TDC timing marks don`t line up. With a New timing chain and gears installed straight up, Dots lined up. The Balancers timing mark lines up with the 0 on the timing tab, Both I assume are stock. So when I install the cover the mark on the cover don`t line up with the balancer or the timing tab. With the Motor at #1 TDC the marks on the balancer and timing tap lined up, So the balancer didn`t slip, Right. If the balancer spun the marks wouldn`t line u, Right. When I lay the Balancer on the bench and line up the balancer bolts holes and crank key with the cover bolt hole hole and the notch the mark are off. So what`s the problem ?

Thanks Doug


Dragway Regular
Jan 16, 2008
Sounds to me like the balancer is OK as it lines up with TDC, I'm going to say your timing tab on a 305 timing cover is up behind the water pump? And the timing mark on the cover ends up the the left side of the engine more under the water pump aimed at # 1 cylinder? If that's the case you probably have a cover for a 283/307/327, that would be my guess without actually seeing it, Hope it helps! KillerDave


MalibuRacing Junkie
Sep 18, 2006
West, MI
Thanks Killer Dave, Your right on the timing tab. So im thinking the Balancer is off. Its Off about an inch. I lined the balancer timing mark and the TDC on the cover and drilled new holes. Now everything lines up perfect.

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