65 396 & early 66 427

[Mark S. Lovejoy]

Do all 65 396 engines and early 66 427 engines use the odd size 3/8" hex head valve cover bolts? (instead of the normal 7/16" hex) I always thought this was correct but can't remember for sure. Thanks.....

[Joe L.]

Re: 65 396 & early 66 427

Mark-----

If any 3/8" across-the-flats bolts were used on L-78 and early L-72 engines, it's news to me.

[Mark S. Lovejoy]

Re: 65 396 & early 66 427

Joe,

I had the same response.

Cranky has posted it over on the VH board, hence the question.

Thanks.

[Bryan L.]

Re: 65 396 & early 66 427

Paragon has them, listed as 65-66 big block.

BL

[Joe L.]

Re: 65 396 & early 66 427

Mark-----

Yes, I see that he later posted that he "found em [sic]" at Paragon. The link provided shows the Paragon 1741K bolts. He says that although Paragon doesn't describe them, he's sure they are the correct ones. I'm pretty sure they're the correct ones, too. However, I've got news for him----the Paragon 1741K are NOT 3/8" across-the-flats (i.e. wrench size); they're 7/16" wrench size, just like all other big block valve cover bolts. The only thing "unique" about them is the "indented head" (i.e. "untrimmed") configuration. I believe that this feature was, as far as big blocks go, unique to the 65-E66 big block valve cover bolts. However, the same configuration was used on many (but NOT all) small block valve cover bolts right through 1982.

[Robert Jorjorian]

Re: 65 396 & early 66 427

I have news for Joe = Hanson (cranky) is absolutely correct in that the 1965 396 (all of them in 65) used a valve cover bolt with a 3/8" hex not a 7/16" hex with a common head logo being a four leaf clover.

[Joe L.]

Re: 65 396 & early 66 427

Robert------

The Paragon 1741K which your buddy said he was absolutely sure were correct for 65-66 have 7/16" wrench size.

[Dick W.]

Re: 65 396 & early 66 427

Know that at least thru '66 VIN 1,2XX had the 3/8" recessed head bolts

[Joe L.]

Re: 65 396 & early 66 427

Dick----

Like I mentioned, it's news to me. Do you know if any of the C2 era small blocks also used these 3/8" wrench surface bolts? I have never found a 1/4" bolt with a 3/8" wrench surface on a Corvette. However, that doesn't mean that none were used. Maybe I just didn't notice the wrench size when I removed or installed them.

[Dick W.]

Re: 65 396 & early 66 427

Joe, I do not know about the small blocks. Most of the C-2 cars that I worked on had a big block, I guess that we only restored/detailed 2 small blocks, a '66 350 hp and a '67 base engine.