Bolt length for intake manifold, A/C bracket to intake, 402

[71CHEVYSHORTBED402]

Working on a 402 with an original intake manifold. Dry run for A/C assembly

I read you don't want too long of intake manifold bolts because they'll interfere with the push rods. From what I read, the longest bolt you should use is 1.25", which happens to be what's on my truck. Still, the bolts only bite 3/8" from the bottom of the head, so, they'd hardly be on using a shorter bolt.

Page 526 of the assembly manual shows lock washers used for the bracket that mounts to the intake. The bracket is 3/8" thick, so the existing bolts can't very well bite, even without lock washers.

1. Safe to say the bolts used for the A/C bracket on the intake are 1.75" long? Just looking for confirmation so I don't jack something up. That and interested in other insights.

2. Were lock washers used on all the intake bolts? My truck just has bolts (no lock washers). I don't see a reference in the manual, at least not via the index anyway.

Thank you

[71CHEVYSHORTBED402]

Any particular reason I should not use grade 8 bolts for that bracket on the intake? I ask because grade 8 are the only black phosphate, hex flange bolts I can find in 3/8-16 x 1.75. The existing intake bolts are grade 5.

Other than that, I found a couple of double side studs, which may have come from this truck. So happens one end of these are 1.75" long. Still, the book only shows bolts and L-washers. That and the studs would suggest something was mounted on top. Shame I wasn't paying attention when I removed the A/C some 25 years ago.