L71 balancer pulley

[William O.]

Any one know the correct balancer pulley for a 67 L71.....I know its 3863108......but is it BF...or BM...or is it the one with the cast numbers on the front edge and not next to the windows.....I guess what i am asking is which one passes judging

[Richard M.]

Re: L71 balancer pulley

I searched "3863108" and came up with a few interesting threads. Not conclusive but there are a few photos of each type in the posts. The L71 I worked on a few years ago used the reproduction, with the part# cast on the outer edge. Not sure how it would judge. The JM does not specify features.

Rich

https://www.forums.ncrs.org/showthre...hlight=3863108

https://www.forums.ncrs.org/showthre...hlight=3863108

All search results here....3863108



348gbkn.jpg

[Wayne M.]

Re: L71 balancer pulley

I thought that top pic looked familiar . [is on my late 396]

[Joe L.]

Re: L71 balancer pulley

Any one know the correct balancer pulley for a 67 L71.....I know its 3863108......but is it BF...or BM...or is it the one with the cast numbers on the front edge and not next to the windows.....I guess what i am asking is which one passes judging

William-----

If I recall correctly (and I may not), the "BF" broadcast code was used for the GM #3921923 stamped steel pulley used for many 1968-74 Corvette big blocks

Correction: I had it backwards, The "BF" broadcast code was used for the cast iron GM #3863108 pulley and the "BM" broadcast code was used for the stamped steel GM #3921923 pulley. How the cast iron pulley pictured in this thread got the "BM" code, I have no idea. The 2 pulleys are functionally interchangeable but there would have needed to be different broadcast codes so that assembly line workers knew which pulley to install for a particular application.

[Hebert K.]

Re: L71 balancer pulley

William,
The one that is on my 67 L71 is 3863108 BF.