Topic: 1968 390GT/428 smog/alt bracket fasteners

[WT8095]

With no first-hand access to untouched '68 S-code engines, I've spent a lot of time trying to determine the correct fasteners for mounting the alternator and smog pump. The numerous sources I've checked have had conflicting information on fasteners and on finishes. My newly acquired '68 engine manual sheds some additional light, and agrees with a "consensus" pattern that was starting to emerge from the other data. But the big question is - what really made it onto engines on the assembly line?

I've attached the chart from the thermactor page. The alternator pivot bolt and washer are not shown on this page, but on the alternator page they are listed as:

Bolt: 302569-S8
Washer: 34793-S8

I'm looking for feedback on the fasteners and the finishes. Hopefully field observations will confirm what's on the drawing. If not, this is the place to set the record straight. Final results will be sent to Jim to include in his spreadsheets.


This is the raw data for just the four bolts that go through the combo bracket. Note that there is even a conflict within the 68 engine manual regarding the length of the lower right bolt!

Type      Loc.    Function       MPC code    MPC chart    MPC illus    69 eng      67 eng (JWC)    68 trk eng    68 eng t/e    68 eng alt    Most likely
Bolt      UR      Attach to WP   53          42996-S7-8   42996-S      42997-S36   42997-S8        42996-S8      42996-S2      N/A           42996-S2
Bolt      LR      Attach to WP   53          42996-S7-8   42998-S      42998-S36   42997-S8        42997-S2      42998-S2      42997-S2      42998-S2
Bolt      UL      Pump pivot     75          45644-S8     301005-S     301005-S2   N/A             301005-S2     301005-S2     N/A           301005-S2
Bolt      LL      Alt pivot      26          375860-S2    N/A          302569-S2   N/A             302569-S8     N/A           302569-S8     302569-S8
Washer    LL      Alt pivot      N/A         N/A          N/A          34793-S2    N/A             34793-S8      N/A           34793-S8      34793-S8

Edit: removed '67 alt bolt & washer - application is different from '68.

[rockhouse66]

Not a direct response, but I would just mention that the It. 9 adjusting bracket bolts I have on original pumps have a different head marking than the bolts provided by AMK for this application.

[WT8095]

Not a direct response, but I would just mention that the It. 9 adjusting bracket bolts I have on original pumps have a different head marking than the bolts provided by AMK for this application.

I think it would be great to add observed head markings to this discussion, since it's such a narrow topic. What one(s) have you seen?

[jwc66k]

The 67 390 smog pump pivot bolts are 370584-S8 or 300916-S8. They are in the spreadsheets but I can see an area that I need to review to standardize descriptions.
Jim

[rockhouse66]

AMK repro on the left with the "F" and original on the right.

[WT8095]

The 67 390 smog pump pivot bolts are 370584-S8 or 300916-S8. They are in the spreadsheets but I can see an area that I need to review to standardize descriptions.
Jim

Thanks Jim, I believe I made a cut & paste error. But now I see that the '67 bolts are 4" long as opposed to 5.75" for '68 & up. '67 bolted to a bracket, didn't it? I'm going to take that out of my spreadsheet since it's comparing apples & oranges for the purpose of what I'm doing here.

[jwc66k]

AMK repro on the left with the "F" and original on the right.

What are the dimensions, and part number? A picture doesn't always tell the whole story.
Jim

[rockhouse66]

They are dimensionally identical - it is just the head marking that is at issue here.