1970 aluminum intake bolts

Ken70

Member
Jul 14, 2018
85
Can anyone tell me the correct intake bolt for 1970 SB with aluminum intake ? I see ones with washers and ones with a shoulder part of the bolt? I know 4 are longer for corners holes.

Thanks in advance
Ken
 

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FS87LT

Veteran Member
Apr 3, 2010
243
DFW, TX
Not having a parts book handy, I suspect the flange-head bolts would be correct. Reason is that on the engine production line, having normal bolts and then putting flat washers on them would be an extra labor operation that would have to be done off-line by a worker, whereas the flange-head bolts did not need this, hence less cost. AND, one less thing to be deleted by a flaky worker, possibly.

If you have access to a Chevy parts book, look in the "Standard Parts" (i.e., nuts, bolts, washers, etc.) and you can probably find a then-good GM part number and the "minimum order quantity" listed for the particular sizes needed.

I found some Grade 8 sub-frame body-mount bolts that way.

FS87LT
 

70lt1z28

Veteran Member
Gold Member
Oct 3, 1999
5,084
Beavercreek, Ohio, USA
They were standard bolt heads, no flanges or washers and were manganese phosphated. The exception is the engine lift bracket bolts which were zinc plated flanged bolts. There was also silver overspray on some and orange overspray on the plug tower bolts.
 

Ken70

Member
Jul 14, 2018
85
Thanks guys - like they say a pic says a 1000 words . Can’t argue with them .
 
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