Head bolt question
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Instructor
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From: Thorntown IN
Head bolt question
Why do most small block head bolt kits come with 3 length bolts when the 2 middle length bolts provided will not work on my 283s. All bolts under cover are same length. Need explanation.
Don
Don
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Regards
Pro
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Pro
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55-61 Corvette 14 at1 3/4"
55-61 Corvette A.R. 3 3/4"
59-61 Corvette 4 at 3"
They made several changes on the 59 and later heads.
Some of these were
Bolts which held valve cover became straight line.
Coolant passage in spark plug area
I believe the change which created the need for shorter headbolts was a depression on each end of the heads which aided in oil return to the sump.
Regards
Thread Starter
Instructor
Joined: Aug 2006
Posts: 248
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From: Thorntown IN
head bolts
Seems a lot of books state 3 length bolts for all 283s. I do know my original 770 heads on my original 739 block in my 58 had only 2 lengths. I am currently arguing with a head bolt seller who thinks I am crazy.
That may have some merit but with this issue I can say I am correct. He wont send me 4 long bolts to replace the 4 middle size that was sent.
Central did not know this either and told me they are going to create a new part number.
I know what I would be doing about now back in the late 60s. Crank up the Doors and partake in.....
Don
That may have some merit but with this issue I can say I am correct. He wont send me 4 long bolts to replace the 4 middle size that was sent.
Central did not know this either and told me they are going to create a new part number.
I know what I would be doing about now back in the late 60s. Crank up the Doors and partake in.....
Don
Team Owner
Joined: Oct 2000
Posts: 38,897
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From: Washington Michigan
283's use two of the 3" (intermediate) length bolts on each head, under the valve cover, at the lower corner at each end. 1961 Passenger Car Shop Manual verifies it, and calls it out as a special note.
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Regards
Thread Starter
Instructor
Joined: Aug 2006
Posts: 248
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From: Thorntown IN
head bolts
John, THANKS for reply. That makes 2 of us now. Can you have a copy from your book that states that. I am dealing with a PIN HEAD parts supplier who can read but has zilch common sence. I would like to educate him to get my 4 bolts and get away from a paypal dispute. He
p...ed me off with an attitude & Im not letting him off. Thanks
Don
Sending a pm
p...ed me off with an attitude & Im not letting him off. Thanks
Don
Sending a pm
Race Director
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Well, let me jump in here right quick
John Z REALLY shocks me on this one.
Sooooooooooooooooooo, everyone read the following carefully.
FIRST, I don't give a big flying flip what ANY book or what ANY fastener manufacturer says or states in their literature.
Here is what is fact. Period. End of discussion. Forget the book(s), GO GET THE HEADS AND CHECK IT OUT FOR YOURSELF!!!
The VERY EARLY SB heads used TWO, repeat, TWO lengths of head bolts---------------NOT THREE!!!!!!!!
I do not know the exact cutoff date, but the 55 to APPROXIMATELY 58 265 and 283 heads had ALLLLLLLLLLLLLLLLLLL the same length bolts under the valve cover, and all the bolts on the exhaust side were the short version.
APPROXIMATELY 1959 model 283s, and all subsequent SB heads thereafter used three lengths of head bolts, with the two end bolts being the middle length.
Again, some of you guys surprise me about this!
Don't sit there at the keyboard and argue about it-----------------go locate an early head and check it out!!!
John Z REALLY shocks me on this one.
Sooooooooooooooooooo, everyone read the following carefully.
FIRST, I don't give a big flying flip what ANY book or what ANY fastener manufacturer says or states in their literature.
Here is what is fact. Period. End of discussion. Forget the book(s), GO GET THE HEADS AND CHECK IT OUT FOR YOURSELF!!!
The VERY EARLY SB heads used TWO, repeat, TWO lengths of head bolts---------------NOT THREE!!!!!!!!
I do not know the exact cutoff date, but the 55 to APPROXIMATELY 58 265 and 283 heads had ALLLLLLLLLLLLLLLLLLL the same length bolts under the valve cover, and all the bolts on the exhaust side were the short version.
APPROXIMATELY 1959 model 283s, and all subsequent SB heads thereafter used three lengths of head bolts, with the two end bolts being the middle length.
Again, some of you guys surprise me about this!
Don't sit there at the keyboard and argue about it-----------------go locate an early head and check it out!!!
Last edited by DZAUTO; Dec 3, 2008 at 10:51 PM.
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Apparently, you know more about this than the people that manufacture head bolts. And you want me to do my research before I confuse somebody else?????
All my catalogs are crap. I threw them in the fireplace. Next time I need a part for something, I will ask your opinion first.
It seems to me that after 40 years you weren't the only one to inform these manufacturers that they were wrong. Why didn't they do anything about it?
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Apparently, you know more about this than the people that manufacture head bolts. And you want me to do my research before I confuse somebody else?????
All my catalogs are crap. I threw them in the fireplace. Next time I need a part for something, I will ask your opinion first.
It seems to me that after 40 years you weren't the only one to inform these manufacturers that they were wrong. Why didn't they do anything about it?
All my catalogs are crap. I threw them in the fireplace. Next time I need a part for something, I will ask your opinion first.
It seems to me that after 40 years you weren't the only one to inform these manufacturers that they were wrong. Why didn't they do anything about it?
18 long bolts at 3 3/4in length
16 short bolts at 1 3/4in length
AND, while we're on the subject of catalog incorrectness, the aftermarket Chevy catalogs that list the gear ratio discs for rearends (56-62 Vettes and pass cars up to 64), have the listings/illustrations for the 3.36 and 3.55 discs reversed and refuse to change them.
Last edited by DZAUTO; Dec 4, 2008 at 07:52 AM.
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Thank you
I do agree that there was a mid 59 change.
Last edited by john neas; Dec 4, 2008 at 12:13 PM.
Pro
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Head Bolt Clarification
This is the Chevrolet Parts and Accessories Catalog for 1957
It shows that the 1957 Corvette used only two head bolts:
16 at 1 3/4"
18 at 3 3/4"
This is what an intermediate 3" bolt looks like in a 58 3748770 head. (Typical of the 55 - early 59 heads). The bolt will not even go into the block and provide the necessary clamping force.
This is the same intermediate 3" bolt in a 64 3782461 head (typical of the late 59 and later heads). It will hold the head and head gasket to the block.
This picture shows the location of the long bolt early head (this is the same location which uses the intermediate bolt on the later heads)
This picture shows the same location on the later head which uses the intermediate bolt. The location was sunken which required the shorter bolt.
bigblock 67, hopes this helps you.
Regards.
Drifting
Joined: Oct 2008
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From: Rochester Hills Michigan
I'm assuming the change occurred when the cylinder head 3755550 (staggered cover bolts) was replaced by the 3767465 (straight cover bolts). NCRS Judging Guide says that occurred between May 5-19, 1959. Staggered covers may appear on cars assembled as late as July 1959.
Pro
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I'm assuming the change occurred when the cylinder head 3755550 (staggered cover bolts) was replaced by the 3767465 (straight cover bolts). NCRS Judging Guide says that occurred between May 5-19, 1959. Staggered covers may appear on cars assembled as late as July 1959.