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Hot Rods Let's talk Cadillac 331's, 365 and 390's

Discussion in 'The Hokey Ass Message Board' started by Roothawg, Apr 7, 2016.

  1. 42Merc is correct; the Studebaker rockers are 1.5:1 while the late Cad rockers are 1.6:1 ratio. To run the adjustable Stude rockers on the Cad will require custom pushrods to get the length and ball ends right. Also dimpled valve covers or custom valve cover spacers for clearance, or finding a vintage set of Edelbrock or Hildenbrant covers. A real pain, but if you need adjustable rockers you'll just have to do it. A couple of other options would be finding a set of usable McGurk or other aftermarket rockers, or see what Rocker Arms Unlimited could do for you.

    Regardless what you do, you'll want to be damn sure you have the rocker shafts installed correctly...
     
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  2. Roothawg
    Joined: Mar 14, 2001
    Posts: 17,241

    Roothawg
    Member

    I guess my question is this. Do I really need adjustable rockers? On a hyd cam, it would seem to be a moot point. I plan on rebuilding everything to new specs, so is this something I need?

    I don't like the looks ofthe dimpled covers, but that's about all you can find these days. I could chrome the original ones I suppose.
     
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  3. HiHelix
    Joined: Dec 20, 2015
    Posts: 353

    HiHelix
    ALLIANCE MEMBER

    Anyone with a 1960 Cadillac who wants the owners manual micro fiche... I have one reel.... free come pick it up...
     
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  4. Moriarity
    Joined: Apr 11, 2001
    Posts: 10,927

    Moriarity
    SUPER MODERATOR
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    It is my understanding that you need adj rockers or custom length pushrods if the base circle of your new cam is different than stock
     
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  5. Roothawg
    Joined: Mar 14, 2001
    Posts: 17,241

    Roothawg
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  6. clunker
    Joined: Feb 23, 2011
    Posts: 1,419

    clunker
    ALLIANCE MEMBER
    from Boston MA
    1. MASSACHUSETTS HAMB

  7. Roothawg
    Joined: Mar 14, 2001
    Posts: 17,241

    Roothawg
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    They said I would need to run the adjustable rockers, no explanation. Maybe to address the pushrod length difference?
     
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  8. Johnboy34
    Joined: Jul 12, 2011
    Posts: 817

    Johnboy34
    Member
    from Seattle,Wa

    Or maybe pick a different cam so you can run Cad rockers. My son had a cam ground here and uses Cad rockers, sounds good too! http://www.deltacam.com/
     
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  9. Roothawg
    Joined: Mar 14, 2001
    Posts: 17,241

    Roothawg
    Member

    Johnboy, I would but I don't know where the line is drawn. At what point are adjustable rockers required? Any idea on the specs for your son's cam?

    Update****Just got off the phone with Delta and they are pretty helpful. He said that the manufacturer that used to supply all the cams has quit making Caddy stuff altogether, so you will either get NOS or have your core reground. He said the max lift would be in the .450-460" range. He said he would then take the number of the base circle removed and you just have custom pushrods built. He only gets $72.50 to regrind your cam.
     
    Last edited: Apr 10, 2017
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  10. Johnboy34
    Joined: Jul 12, 2011
    Posts: 817

    Johnboy34
    Member
    from Seattle,Wa

    I'll see if he still has the cam card, it's not too big and has nice lope to it so you know it's not stock. Pick up the phone and call Delta and ask some questions, they're good guys.
     
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  11. Roothawg
    Joined: Mar 14, 2001
    Posts: 17,241

    Roothawg
    Member

    I did call them after your post.

    I am perplexed at what he said though. He said the max duration is about 270* and the lift is .450". I see multiple companies advertising at 280* and .480" with a 1.5 rocker.

    The later Caddy is 1.6, which would work out to .512".
     
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  12. Johnboy34
    Joined: Jul 12, 2011
    Posts: 817

    Johnboy34
    Member
    from Seattle,Wa

    I'll have to see what they did on the cam card, I seem to remember my son saying something about a nos blank to grind. I know his motor is a 62.
     
  13. Johnboy34
    Joined: Jul 12, 2011
    Posts: 817

    Johnboy34
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    from Seattle,Wa

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  14. Roothawg
    Joined: Mar 14, 2001
    Posts: 17,241

    Roothawg
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  15. Roothawg
    Joined: Mar 14, 2001
    Posts: 17,241

    Roothawg
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    Yes, I have read this multiple times. Only article out there unfortunately. I wish someone would do a performance build in one of the magazines. We all know you can get 500hp out of a 406 on pump gas.
     
    Last edited: Apr 30, 2017
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  16. Roothawg
    Joined: Mar 14, 2001
    Posts: 17,241

    Roothawg
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    So, can a guy do away with the clunky valve retainers/oil seals on the 390 heads? Maybe go to a lighter retainer and cut the guides for a more modern seal?
     
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  17. Roothawg
    Joined: Mar 14, 2001
    Posts: 17,241

    Roothawg
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  18. Roothawg
    Joined: Mar 14, 2001
    Posts: 17,241

    Roothawg
    Member

    After much research and deliberation, I have come to the conclusion that I am possibly getting out of the Cadillac business. I have spent countless hours on the phone with folks all over the country and I don't think the return on my investment is there. I can't get what I was hoping for performance wise. It has been a learning experience.

    But, knowing how I am, I'll probably get sellers remorse and end up building it anyway. Depends on the mood.
     
    Last edited: May 5, 2017
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  19. Moriarity
    Joined: Apr 11, 2001
    Posts: 10,927

    Moriarity
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    oh man.... really? sorry to hear that...
     
  20. Roothawg
    Joined: Mar 14, 2001
    Posts: 17,241

    Roothawg
    Member

    No biggie, I just wanna go a little more towards the performance side of things.
    I am looking into a Nailhead now. That was the original plan and I got mesmerized by the Caddy. A lot more parts availability for go fast stuff.
     
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  21. c322348
    Joined: Nov 28, 2007
    Posts: 269

    c322348
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  22. Roothawg
    Joined: Mar 14, 2001
    Posts: 17,241

    Roothawg
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    There's several things in the article that look to be wrong. Inthat same paragraph #25, it talks about a 4" stroke. Nope, 3-7/8".
     
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  23. Roothawg
    Joined: Mar 14, 2001
    Posts: 17,241

    Roothawg
    Member

    The main reason I kinda thought about abandoning the Caddy was this article we talked about previously.
    https://www.jalopyjournal.com/forum...ay-2008-anyone-have-it.1060661/#post-12037292
    I had heard about this article forever and finally got to read it. They did all the mods I had planned and lost like 40hp and quite a bit of torque over a bone stock rebuild. That too the wind right out of my sails. I wonder if anther shop would have had the same results? The Torquey 365 build was basically the same build and their HP stayed the same and the torque went up. I would hope that running the 2x4 and a later style carb, like the Holley 390's would net a better result.

    I hate to abandon it.....talk me into it.
     
  24. c322348
    Joined: Nov 28, 2007
    Posts: 269

    c322348
    Member

    Breathing was always a problem with the Caddies of that vintage. One of the first things rodders always did was install an aftermarket intake.

    Later Caddies featured a low hood line requiring a manifold that was really squashed down. OK for torque, but not for RPM.

    My dad had a stock 331 and the valves would float much above 3,000 RPM due to the low spring pressure.

    I'm correcting all these things on my build, we'll see how I do. A lot of Caddies were raced back in the day, even in dragsters, so there must be some secrets waiting to be rediscovered!


    Sent from my iPhone using The H.A.M.B. mobile app
     
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  25. Roothawg
    Joined: Mar 14, 2001
    Posts: 17,241

    Roothawg
    Member

    I have been trying to find "That guy" that knows, loves and breathes old Caddys from back in the day. I have started asking the old racers around here, but no luck yet.
     
  26. clunker
    Joined: Feb 23, 2011
    Posts: 1,419

    clunker
    ALLIANCE MEMBER
    from Boston MA
    1. MASSACHUSETTS HAMB

    At least you created an awesome thread or two with tons of good info for people rodding with Caddies. Looking foreword to your Nailhead threads! I think you are going to make some money back reselling that manifold and other stuff.
     
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  27. Roothawg
    Joined: Mar 14, 2001
    Posts: 17,241

    Roothawg
    Member

    Thanks. Glad it is useful.

    As far as parts go, it is so hard to come by, I hate to sell any of it.

    I'll probably buy the nailhead I have located for future projects, even if I build the Caddy.
     
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  28. falconsprint63
    Joined: May 17, 2007
    Posts: 2,263

    falconsprint63
    Member
    from Mayberry

    there's an alard racing site with some good caddy tech from way back. don't remember what it is right off but I'll do some looking

    Sent from my SM-G920R4 using The H.A.M.B. mobile app
     
  29. falconsprint63
    Joined: May 17, 2007
    Posts: 2,263

    falconsprint63
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    from Mayberry

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  30. Johnboy34
    Joined: Jul 12, 2011
    Posts: 817

    Johnboy34
    Member
    from Seattle,Wa

    If you just use one with just a little bit more cam, for the torque it produces, set up the rpm ranges to use it in a light weight old rod, it is tough to beat for nostalgia! And fun, and gets with the program. If on the other hand you want to make more of a race motor then I agree there are other alternatives.
     

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