70 Big Block Alternator Bolt and Washers

[Allen N.]

https://www.forums.ncrs.org/showthre...ternator+bolts

The above post shows a picture of a small block alternator bolt with a star washer and it looks like an oversized plain washer for the bolt holding the alternator to the adjusting bracket. Are these the same for a big block? The AIM UPC N40 Sheet A7 has no part numbers for this bolt and the two washers. Could someone please describe these items and their finishes?

Thanks.
Allen

[Mark E.]

Re: 70 Big Block Alternator Bolt and Washers

Allen,

See photo M 12.29 on page 153 of the JG. No written description but looks like a grade 5 bolt with a flat washer under an external star washer, all zinc or cad plated.

[Joe L.]

Re: 70 Big Block Alternator Bolt and Washers

https://www.forums.ncrs.org/showthre...ternator+bolts

The above post shows a picture of a small block alternator bolt with a star washer and it looks like an oversized plain washer for the bolt holding the alternator to the adjusting bracket. Are these the same for a big block? The AIM UPC N40 Sheet A7 has no part numbers for this bolt and the two washers. Could someone please describe these items and their finishes?

Thanks.
Allen

Allen------


The big block with N-40 uses a completely different alternator mounting configuration than small block with or without N-40. So, there is no corollary fastener hardware between big block and small block.

Big block without N-40 uses the same bolt and washer as small block with or without N-40.

[Allen N.]

Re: 70 Big Block Alternator Bolt and Washers

Figure M 12.0 shows an early 70 with a split washer.

Figure M 12.29 shows a 70 with a star washer.

i am still confused.

[Gary B.]

Re: 70 Big Block Alternator Bolt and Washers

Fig. M 12.0 is a 1970 LT1, 350-370hp. Early car, 1-owner, owned by our Advanced Judging School instructor.
Fig. M 12.9 is a 1970, 454 with power steering. 11k mile car. Sitting in what "We" refer to the library along with several other low mileage original unrestored cars. Could either of them been changed? Yah, maybe. Maybe not?
Alan Strucks 71 is a January 1971 built base motor 4-speed car. But the picture he posted was from a 69 small block. They are different than 70 base motors and LT1's . Why? Who knows. Cost?
Are you asking about 70 454 with PS? If yes, use use what Fig. M 12.29 shows. Probably won't go wrong doing that.
Gary B

[Allen N.]

Re: 70 Big Block Alternator Bolt and Washers

Thank you very much for the responses. I will go with Fig. M 12.9.