Harmonic balancer with fins

[Gene M.]

Re: Harmonic balancer with fins

Tom-----


There was only one balancer I know of that ever had "fins". This was the GM #3817173. This balancer was used for all 1962-68 327 applications using an 8" balancer (i.e. L-76, L-84, L-79). It was also used for 1967-68 Z-28 (but not 1969 Z-28 which had a revised timing mark).

However, not all examples of this balancer actually had the "fins". Some folks think that at least all of those used in PRODUCTION and available in SERVICE during the same period had the fins. I don't think so, though. I think the fins may have been eliminated about 1967.

Yes, correct you are. Early 68 L79 more of no fins (only in my findings) than fins. But you will find both.

[David L.]

Re: Harmonic balancer with fins

Were there two different manufacturers of the 3817173 finned balancers?

I have owned or seen many stamped Chevrolet balancers in the past 30+ years. Here are the ones in my notes:

"H6903", "H7" (Aug. 1967)
"2223", "224 71" (224th day of 1971)
"2222H", "080 72" (80th day of 1972)
"H8652", "030 78" (30th day of 1978)
NOS "H6903", "225 82" (225th day of 1982)
NOS "H6903", "092 86" (92nd day of 1986)
"H6903", "230" (230th day of ????)

"7704", "AS0" (from 1970 Monte Carlo w/replacement block)
"7701", "1S0" (from 1971 Chev. 350 block cast. date "1B12" or Feb. 12, 1971)

"E6F" (May 1966 from 66 Chev. 327)
"6904F", "H7" (Aug. 1967)
"4684", "C8F" (March 1968)
"4684", "E8F" (May 1968)
"7706", "J8F" (Sept. of Oct. 1968)
"6904", "A9F" (Jan. 1969)
"7704", "B9F" (Feb. 1969)
"2223", "J1F" (Sept. or Oct. 1971)
"7706", "01F" (???, 1971)

Based on the stampings above there seems to be 3 different manufactures as indicated by the letters "H", "S", and "F".

Dave

[Richard T.]

Re: Harmonic balancer with fins

I have a 62 and 63 finned balancers and both are dated. I also have an NOS 7173 balancer still in the GM box without fins. I've had it a long time but can't recall exactly when I bought it.