57 balancer question??

**Joseph L.** · February 26, 2017, 11:43 AM

Re: 57 balancer question??

Hi John

I have a 57 270HP and am looking for information on the exact configuration for that balancer too.

The new JM show a picture of the "riveted crankcase pulley" with balancer. That balancer has a small step protruding from the front, where the ID of the pulley is located by the OD of this step. The OD appears to be about 2". There is also a photo of the bolt on pulley for the 283HP engine that shows the PN "3742991 GM."
The 1957 AIM (page 579 1.01) shows this pulley PN 3742991 "used with high lift cam."
There is also a table in the JM that identifies 245, 250, 270 HP using a 1/2" wide pulley riveted to the balancer. All others use a 3/8" wide pulley riveted to the balancer.

The 1958-60 JM shows a photo of the 58-59 balancer PN 3760584, and 'early 58 cars had the 3742991 pulley bolted to this balancer.' It does not have the small 2" OD step that is shown on the balancer in the 1956-7 JM. Also, it has no holes on the outer band. I have what appears to be a 3760584 balancer with no holes.

We are both looking for the same balancer assembly.
More specifically for both of our cars, is the correct configuration; the 3760584 balancer riveted to the 3742991 pulley? Does someone have a photo of that part or can comment on the configuration?

Joe

**John R.** · January 31, 2018, 07:44 PM

Re: 57 balancer question??

Posted this a while ago. Would love to know the correct configuration on the balancer/pulley for a very late 245 hsp. Also, while we are at it, would I use the stepped waterpump pulley or not?

**John R.** · February 1, 2018, 07:12 AM

Re: 57 balancer question??

I see from researching, the 245hsp engine uses the 1/2 inch generator and waterpump (stepped) pulley. So that must mean the crank pulley is 1/2 too. This is a very late car assembled during the last couple days of production in late August 1957. Last piece of information I need is to confirm the configuration of the crank pulley and balancer. Is it the 1/2 inch pulley riveted to the balancer or 991 (1/2 inch) pulley bolted to the balancer?

Thanks in advance to anyone who can help. Want to get this correct the first time

**Gary C.** · February 1, 2018, 08:13 AM

Re: 57 balancer question??

John,

Pulleys and balance applications are listed in the 1956-57 Judging Manual.

Gary
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**John R.** · February 1, 2018, 06:20 PM

Re: 57 balancer question??

Gary, thanks for the direction. Here is what the JM says. Not so clear, thus hoping someone can assist. Thank you.

Attached Files

WP_20180201_19_17_08_Pro[1].jpg (62.5 KB, 45 views)

**Gary C.** · February 1, 2018, 06:33 PM

Re: 57 balancer question??

There's been two 56-7 Judging Manual revisions since that manual.

Suggest, you purchase a new 56-7 JM. Lots more information and photos.

Gary
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**John R.** · February 1, 2018, 07:19 PM

Re: 57 balancer question??

Gary, I will buy a new 57 JM when I get closer to getting serious about having this car judged. Who knows that may be never or 3 revisions to the JM by that time! Was hoping someone on this board could help a fellow member. Hope that is not too much to ask.

**Perry M.** · February 1, 2018, 10:06 PM

Re: 57 balancer question??

it's not to much to ask. Somewhere in my unpacked files lies the information you need, I recently relocated and all my literature is still in boxes. I know from restoring my factory fuel injected 57 Nomad back in the 80's that you need a 1/2'' riveted pulley. All 245, 250, and 270 horse power engines used the 12'' riveted pulled. The water pump pulley was also 1/2'' wide and it was stepped. The generator pulley was also 1/2''. There was a difference in the 1/2'' generator pulleys. Original 57 pulleys had round spot welds on the face verses rectangular shaped spot welds. The 283 horsepower motors used the 991 bolt on pulley. All turboglide equipped passenger cars also used the 991 bolt on pulley. That's probably why they are easier to find than the riveted pulley because they were more prevalent. If you need a generator or water pump pulley, let me know. Perry

**Dan P.** · February 11, 2018, 08:45 AM

Re: 57 balancer question??

I will post one later. You can also find the balancer on trucks . I think Gary Pronesti has the balancer you need .

**Dan P.** · February 12, 2018, 07:32 PM

Re: 57 balancer question??

If remember correctly not all had the part number and some were stamped on the back side . There were also two styles of pulleys . I do not have a picture of the other style

Attached Files

**Mike M.** · February 12, 2018, 08:24 PM

Re: 57 balancer question??

dan: I'd loose the bolt/thick washer retaining the balancer/pulley to crank snout for judging . regards, mike

**John R.** · February 12, 2018, 10:05 PM