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Staggered bolt to straight bolt valve cover adapters?

Discussion in 'The Hokey Ass Message Board' started by 46stude, Dec 13, 2004.

  1. 46stude
    Joined: Mar 3, 2004
    Posts: 1,718

    46stude
    Member

    Is there an adapter out there that'll let you run the old style staggered bolt SBC valve covers on the later straight across design heads? I've found adapters to run straight across style covers on post-'86 SBC center bolt style heads, but nothing for what I'm looking for.
     
  2. dadseh
    Joined: May 13, 2001
    Posts: 526

    dadseh
    Member

    Drill some new holes maybe???.... seriously some guy told me the staggered covers were off early Corvette...true?
    I had a set of these heads on my 283 , and they had big valves.
    So where did they come off?

    dadseh

    " what if there were no hypothetical questions?"
     
  3. Staggered bolt covers were simply the early style. Chevrolet changed to straight-across bolts in 1959, IIRC.
    So, they are NOT a Corvette-only item, but they ARE a 265 ONLY and first two years of 283 item.
    Cosmo
     
  4. Donzie
    Joined: Aug 9, 2001
    Posts: 2,779

    Donzie
    Member

    I had a pair of early Vette covers that had been chromed. I looked high and low for adapters and never found any, so I put a pair of 265 heads on my 327. Fooled a lot people. Especially if you run a generator.
     

  5. 46stude
    Joined: Mar 3, 2004
    Posts: 1,718

    46stude
    Member

    I was afraid there weren't any on the market. The set of 'Vette covers I have are off one of my Dads '57 Chebbies he drove at the local short tracks in the late '60s, 283 powered. I want to use them cuz of thier "history". Looks like I'll be searching a set of early SBC heads. Thanx for the help. [​IMG]
     
  6. Hackerbilt
    Joined: Aug 13, 2001
    Posts: 6,254

    Hackerbilt
    Member

    I have the same covers.
    Thought about adapters but decided against it...two gaskets and a higher mounting location.

    I'm going to make a jig off a staggered cover and use the jig to locate the mounting holes to the head and act as a drill guide. The holes will be drilled deeper into the head for strength and to allow for the thinness of the cover rail in that area. The Vette cover has a 1" or so tube that the bolt passes thru so that will help keep the twisting strain off the thin part of the head flange.
    STUDS will be used, not bolts.

    REMEMBER to use a drill bit to fit the TAP, not the bolt!!!

    If some cracking or chipping takes place on the head flange I'll fix it with a little brazing.

    Thats my PLAN. Didn't do it and who knows, might ruin a head trying it...but they are cheap and I'll get them rebuilt AFTER the modification just to be safe, not before.

    BTW...
    SOMEBODY was making those adapters here on the HAMB.
    Can't remember who it was... [​IMG]
     
  7. OldSub
    Joined: Aug 27, 2003
    Posts: 1,064

    OldSub
    Member Emeritus

    I have a set of those valve covers too.

    I was thinking about cutting the lower portion off and replacing it with the lower portion from a later valve cover.

    They are sitting in a corner, and I've not compared them to the later covers to see if they are close enough for this to work. Has anyone else tried that approach?
     
  8. Dakota
    Joined: Jan 21, 2004
    Posts: 1,535

    Dakota
    Member
    from Beulah, ND

    I have saeen people just drill the head on the gasket surface with the 2 extra holes for the staggered pattern on the newer heads. i dont know much as far as leaks and such,m but i dont hink that should be much of an issue.

    id just drill the head, less they are some irreplaceable rare casting or something.
     
  9. Flat Ernie
    Joined: Jun 5, 2002
    Posts: 8,406

    Flat Ernie
    Tech Editor

    I have a set of early Corvette staggered valve covers I was going to put on my A roadster (sold it though & still have the staggered valve covers). I found a couple places that sell adapters for staggered/straight - they weren't cheap though - something silly like $150 for the set. Saw one or two sets pop up on eBay, but always went high. I was going to make my own adapters, but never got around to it.

    So yes, they are out there. The ones I've seen will raise your valve covers up a bit & you do use two gaskets...

    [​IMG]
     
  10. They're pretty easy to make. The last set I made were from 3/8 aluminum plate. I needed the clearance for my valve train, and wanted to run a set of early script rockers I had laying around. Imposter, all rods are imposters, wolf in sheeps clothing or vica versa. [​IMG]
    but you can make them out of a piece of 10-16 gauge steel. they won't hardly show. Drill the sheet for the head and it will mount with countersunk screws. For the stagger cover you drill for the cover and tap and braze studs in then smooth it out and your in there like swimwear. Yea ya still gotta run two gaskets but it works.
     
    LOU WELLS likes this.
  11. Mojo_AL
    Joined: Dec 7, 2003
    Posts: 137

    Mojo_AL
    Member

    For those who don't want to run two gaskets, why not use "liquid gasket" between the adapters and heads. I know most people hate these sealers, but they do the job. Besides, these adapters won't get removed often anyways. I've used lots of sealers on my motorcycle and I like the Caterpilar blue stuff.
     
  12. Southfork
    Joined: Dec 15, 2001
    Posts: 1,465

    Southfork
    Member

    For my early valve covers, I figure to buy the early staggered-bolt heads. I know a guy that has several sets stored in a school bus. Are any of the early heads better than the others? What casting numbers are best? When you got a choice of several sets of heads, might as well be selective --- if there is a difference. With the later double humbers, the casting numbers are all well-known, but I don't have a clue about the pre-"fuelie" heads as far as what to look for.
     
  13. fab32
    Joined: May 14, 2002
    Posts: 13,985

    fab32
    Member Emeritus

    Flow (hp) wise, all heads after '59 are better than the '55-'59 heads and it doesn't make sense to run them just for the sake of using the staggered covers. I'd only do this if I HAD to have the covers, but with the number of Corvette covers out there with the straight holes I'd go that direction and make wall hangers out of the pre'59 covers.

    Frank
     
  14. 46stude
    Joined: Mar 3, 2004
    Posts: 1,718

    46stude
    Member

    Fab32 & my Dad said almost exactly the same things about running the old style heads. Its not worth the loss in HP. Maybe I'll track down some TurboFire 327 valve covers instead & leave the 'Vette ones in the garage on the wall. I'll see when I actually get a 307/327 to work with. Thanx for the input.
     
  15. noboD
    Joined: Jan 29, 2004
    Posts: 8,459

    noboD
    Member

    porknbeaner, if you are going to use 10 g. for the adapter, countersink the cover holes from the bottom and braze flathead screws from the bottom to be used as studs and hold the covers on with nuts. The head screws are countersunk on top and held on the head with flatheads as you said. The common bottom screws are replaced with longer studs and nuts.
     
  16. thefalconer
    Joined: Aug 28, 2012
    Posts: 51

    thefalconer
    Member

    I'm a little late here, but I'd like to put the Stamped "script" valve covers on my pick up... I've found a staggered set, but I'm putting them on an 80's 305. Are all the holes off? or just one? Could I just weld all four holes shut and drill them out in the square pattern, or is there some kind of clearance issue? Thanks in advance!
     
  17. thefalconer
    Joined: Aug 28, 2012
    Posts: 51

    thefalconer
    Member

    I should make it clear that I mean welding the holes on the valve cover, not the head.

    By the way, this is my truck...
     

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  18. Hnstray
    Joined: Aug 23, 2009
    Posts: 12,355

    Hnstray
    ALLIANCE MEMBER
    from Quincy, IL

    One pair of holes are "off". The two along the upper edge are closer together than the lower pair, hence "staggered". You will notice there is recess in the valve cover side wall at each bolt hole ........that is why it is not so simple to just "weld and re-drill". Besides which, that would destroy the very characteristic (staggered holes) that many users are trying to retain.

    Ray
     
  19. adapters are available and work fine. you will need two sets of gaskets. it will raise the covers up a little but that may be a good thing if you have special rockers.
     
  20. COCONUTS
    Joined: May 5, 2015
    Posts: 1,163

    COCONUTS

    I saw a vendor last summer, who was machining adapters to use early style Chevy valve covers on later model heads at the big Carlisle auto parts. I will post the address when I find the card. I have both styles of heads, on hand, and when building my 283, I forgot about the difference and took the wrong heads in for machine work. I was not until the motor was in the car, valves adjusted, engine running (to fine tune the valves), that I tried to fit the old style Corvette valve covers to my later model heads. I ended up using the regular script valve covers, which is OK, because everyone who see the motor, will ask me, if I am going to chrome or polish alum. valve covers.
     
    wraymen likes this.
  21. ^I remember seeing some at Carlisle also. I have a card from Dan Medice of "Head Space". Not sure if this is the guy you are talking about. He did make some nice spacers though but not cheap.
     
    lothiandon1940 likes this.
  22. COCONUTS
    Joined: May 5, 2015
    Posts: 1,163

    COCONUTS

    Yes, that is the person. He does good work, excellent "form, fit, and function".
     
  23. aaggie
    Joined: Nov 21, 2009
    Posts: 2,530

    aaggie
    Member

    An idea that might help but would be expensive would be to get a set of the Vortech centre bolt heads then use the $89 adapters from Speedway that is drilled for the staggered valve covers. The 220CC intakes really flow more air than your engine can use and you will need a Vortech intake manifold but in the end you will have a serious increase in HP and your old valve covers.
     
  24. thefalconer
    Joined: Aug 28, 2012
    Posts: 51

    thefalconer
    Member

    Thanks for clearing that up! I'm not after the staggered hole look, so I guess I'll be looking for some later model covers. Having two gaskets doesn't sound like very much fun and overall against my philosophy of "keep it simple stupid!"
     
  25. von Dyck
    Joined: Apr 12, 2007
    Posts: 678

    von Dyck
    Member

    Hacker has the right idea - drill and tap and use studs to fasten the covers. I've done it. works great. Tip: clamp a piece of steel to the rail before you drill. Your hole needs to be toward the outer edge of the rail.
     
  26. doinbad
    Joined: Sep 17, 2012
    Posts: 324

    doinbad
    Member
    from celina tn

    Is this the covers you are looking for stamped scripted steel non staggered ImageUploadedByH.A.M.B.1448911883.849837.jpg
     
    thefalconer likes this.
  27. rjones35
    Joined: May 12, 2008
    Posts: 865

    rjones35
    Member

  28. 40 & 61 Fords
    Joined: May 17, 2006
    Posts: 1,999

    40 & 61 Fords
    Member

    A buddy put staggered valve covers on his motor to mess with people. It has trick flow aluminum heads on it, and he just welded some material where the bolt needed to be, then drilled and tapped it. With the heads painted, and the squared edges rounded off, you have to do a double take to realize they are not early heads!
     
  29. blue 49
    Joined: Dec 24, 2006
    Posts: 1,820

    blue 49
    Member
    from Iowa

    I had a pair of 1/4" plates plasma cut to make adapters. I took in a new gasket with the extra holes for them to program from. I did my own drilling and countersinking. They leaked a little with 2 sets of gaskets so I used silicone to seal the adapters to the heads, then a gasket for the covers. Not too noticeable with the adapter edges painted engine color. Used on vintage Cal Custom staggered hole covers.

    Gary
     

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