Help I.D. C2 BB lower Alt brkt (no P.S.)

[Wayne M.]

Of the 2 brackets, the upper is the familiar # 3863138 for our L78's or other 396 Passenger '65's (exc. 62 amp). Note the staight horizontal arm, a continuation of the rib under the casting symbol "E" within the triangle. See also the # 1 cast in the crotch of the web. On the backside is only a small "G" enclosed in a circle (also on the web). This bracket holds the alternator so that the pulley lines up with Groove #1 (closest to the engine) for both the water pump and the crank pulleys.

But I can't identify the lower bracket. The elevated arm with the dip to the rear bolt hole usually identifies as '66+, to accomodate the A.I.R. (K19) piping into the exhaust manifold. However, the alternator belt on '66-67 Corvettes was relocated to groove #2, and the bracket 3882810 was introduced, moving the alternator mounting eyelets forward.

I'm thinking that maybe this one is for a '66+ BB Passenger (?), (no P.S.) that has only a single groove pulleys, or that reverts the alt. to groove #1 like the '65s.

Opinions appreciated.

[Joe L.]

Re: Help I.D. C2 BB lower Alt brkt (no P.S.)

Wayne------

It's not the 67-68 Chevelle or Camaro big block bracket which was also used for 66-67 passenger cars with big block.

However, there are several other brackets that it could be. It could be either the GM #3878267 or 3889390 used for 66-67 applications with 62 amp alternator. Or, it could be a bracket used for 66-67 trucks with big block. Or, it could be ?????.

It's too bad that GM did not specify that a part number be embossed on these pieces. It really creates a lot of confusion for this to be missing from pieces like these. I would think that would have been just as true at the time they were used in PRODUCTION as now.

I'm sure that the "E" within the triangle is the ID for the foundry that produced the casting. It was not a GM foundry, so it must have been an outisde supplier. That would be common for a piece like this.

[R N.]

Re: Help I.D. C2 BB lower Alt brkt (no P.S.)

Wayne,

I've a '66 BB, no PS and when I purchase it i could not figure out why my alternator belt was in pos. 1 instead of pos. 2 as it should be. After checking other cars I did notice I had the wrong bracket. (as per the upper brkt. in your picture) I then purchase a new one from GM about two years ago and it is the same as the lower brkt in your picture.

After I istalled the new mounting bracket my alt. belt was move ahead one groove to the correct position on the pully.

IMO, the top picture is the lower alternator brkt. for '65 BB and the lower is for '66 (and later?) I believe these brackets were used on cars w/o PS

Regards,
kurt

[Joe L.]

Re: Help I.D. C2 BB lower Alt brkt (no P.S.)

Kurt-----

The lower bracket does look very similar to the 66-74 non-PS bracket, GM #3882810. However, although it's difficult to say, for sure, from the photo, I don't think that it is. It's hard to describe in words, but the "arm" appears to be further "forward" than the "arm" for the 3882810 which is "set back" further from the centerline of the alternator mounting holes.

[R N.]

Re: Help I.D. C2 BB lower Alt brkt (no P.S.)

My mistake,

i went to the garage to look at the bracket I pulled off, it the same as the lower one in the picture. So the new one I put on my car is like the bracket in the upper position of the picture and not the way i first exlained it. sorry for the confusion.

kurt