57 Balancer pulley info needed

[Michael P.]

I am currently looking for the correct balancer pulley for my '57 270hp motor. Noland Adams book shows one on page 184 and identifies it as p/n 3742991. Currenly there is one on Ebay that "looks" correct and is listed as p/n 3755820. OK, '57 judges should I keep looking or bid?
Many thanks and a happy holiday season to all.

[Gary C.]

Re: 57 Balancer pulley info needed

Michael, sorry don't have any info on the 3755820 pulley other than the 61 P&A lists it's application as 60-61 V/8 hi performance. The 3742991 pulley is 1/2 inch belt deep right pulley. You might post the link and ask for measurements, etc. Merry Christmas, Gary....

[Michael P.]

Re: 57 Balancer pulley info needed

Thanks Gary for your answer. I did contact the seller and he confirms his is not the correct pulley for my application. I will keep looking for the deep groove (1/2") type. Maybe I will be able to find one in January at the NCRS swap meet.
Mike Purton

[Mike B.]

Re: 57 Balancer pulley info needed

Michael,

I am not sure in which year the break occured ('56-'57?), but some of the earlier balancers had the pulley permanently riveted to the balancer; later models used three 3/8" NFT bolts to retain the pulley, thus perhaps the different part numbers.

I can tell you that functionally all balancers (except 8") of the period and for sometime after will fit on the snout and will have the same fore-and-aft dimensions.

But be careful in finding a good balancer. Cars before 1962 simply used an interference fit of the balancer on the crank snout. From 62 on, it was also held in place by a center bolt threaded into the snout. Thus it is especially important that you find a balancer that has not been on and off too many times as the metal will stretch to the point of a sloppy fit. One sure sign to avoid is if it looks like Bubba took a sledge hammer to the front trying to reinstall the balancer. While no guarantee, one without those marks are a better indication that perhaps it was pulled off once and maybe never put back on. The sloppiness can't be repaired so those balancers only make a good paperweights. There are plenty of stories of wobbly balancers coming off and grenading engine compartments!

And I am not sure if 1957 Corvettes used them, but for sure those a few years later used a 1/8" spacer on the snout which acted to move the harmonic balancer forward. This of course puts even less material in contact for the all important friction fit.

Happy hunting!

[Mike M.]

Re: 57 Balancer pulley info needed

i believe all the sbc C-1's used the spacer(to align the pulley of the harm bal with that of the water pump) . the presence of the sbc vette front motor mount dictated use of the washer/spacer.mike

[Gary C.]

Re: 57 Balancer pulley info needed

Michael, check with Gary Pronesti (352) 638-5778 or Pete (918) 968-2366 to see if they have or know of any 3742991 bolt on 1/2 inch deep grove '57 pulley's for sale. Will be Judging 53-7 at the Florida Regional hope to see ya there. Merry Christmas, Gary....

[Michael P.]

Re: 57 Balancer pulley info needed

Gary: Thanks for the leads on the pulley. I will be giving them a call soon. If anybody has one for sale and will be at the NCRS meet in January, please let me know as I will be attending also.
Mike Purton