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Technical Boss 302 rockers on BBC

Discussion in 'Traditional Hot Rods' started by CPT_Kill_Roy, Oct 25, 2019.

  1. CPT_Kill_Roy
    Joined: Feb 23, 2019
    Posts: 118

    CPT_Kill_Roy
    Member

    Any one use the Boss 302 stamped steel needle bearing rockers on a BBC? My how to Hot Rod a BBC book talks about it.
    Adjustments.JPG Adjustments.JPG


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  2. Relic Stew
    Joined: Apr 17, 2005
    Posts: 1,117

    Relic Stew
    Member
    from Wisconsin

    The other way around is common. A lot of manufacturers market their BBC roller rockers for the Boss 302, 351C and 429/460. As a Ford guy, I always cross check part numbers to make sure they are Ford specific rockers, and not Chevy parts. The ratio is close but the geometry isn't quite right. The roller tip isn't centered on the valve. I suspect the same issue the other way around.
    Not sure why you would try to hunt down such rare parts, when performance BBC parts are much easier and cheaper to find. I suspect that book was written when you could order Boss 302 parts at the local Ford dealer, and aftermarket full roller rockers were big money.
     
    Last edited: Oct 25, 2019
  3. RmK57
    Joined: Dec 31, 2008
    Posts: 1,165

    RmK57
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    I think the Ford has a slightly better ratio @ 1.73.
    Harland Sharp make a nice reasonably priced BBF specific rocker.
     
    Last edited: Oct 25, 2019
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  4. Marty Strode
    Joined: Apr 28, 2011
    Posts: 4,168

    Marty Strode
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    I had some of the needle bearing rocker conversions that Ford sold in the early 70's, on my drag car. They weren't very reliable, the trunnion bearings would come apart, and spread the needles along the valve cover rail. Purchased a set of Harland Sharps, problem solved. BTW it was a Boss 302.
     
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  5. Relic Stew
    Joined: Apr 17, 2005
    Posts: 1,117

    Relic Stew
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    from Wisconsin

    I've used Harland Sharps as well. Just street engines, but I don't care for the factory "sled" fulcrum design with higher lift and spring pressure.
     
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  6. CPT_Kill_Roy
    Joined: Feb 23, 2019
    Posts: 118

    CPT_Kill_Roy
    Member

    Thanks for all the replies! I was planning to run basic stamped long slot rockers. I thought it was an interesting tip in my book. My guess is that the Boss 302 rockers will fit a Posi lock rocker kit. So that leads to a second question will a Posi lock fit in to a BBC long slot rocker? Just a note Boss 302 rockers are still sold and easy to find.


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  7. Beanscoot
    Joined: May 14, 2008
    Posts: 1,145

    Beanscoot
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    Are Boss 302 rocker arms different from 351C etc. rocker arms?
     
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  8. CPT_Kill_Roy
    Joined: Feb 23, 2019
    Posts: 118

    CPT_Kill_Roy
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    The boss 302 rockers that are sold new also list 351C


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  9. CPT_Kill_Roy
    Joined: Feb 23, 2019
    Posts: 118

    CPT_Kill_Roy
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    You can see from the photo they have allot more room inside. It seems like the original version has a double nut locking jam nut system. IMG_3400.JPG IMG_3399.JPG IMG_3401.JPG



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  10. CPT_Kill_Roy
    Joined: Feb 23, 2019
    Posts: 118

    CPT_Kill_Roy
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    These adapters from ford racing made them into a “roller” rocker.
    Seems like a good design. Adjustments.JPG Adjustments.JPG


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  11. The rocker setup on the left resembles the 70s olds V/8 rocker design. I replaced about a million of those things. The aluminum fulcrum would eat into the stamped steel rocker until the rockers would click and clack...I always thought it was a terrible design but the illustration of the rocker in the middle appears to be an upgrade. I wonder if it would wear as quickly. 1.JPG
     
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  12. 56sedandelivery
    Joined: Nov 21, 2006
    Posts: 5,857

    56sedandelivery
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    Last edited: Oct 26, 2019
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  13. CPT_Kill_Roy
    Joined: Feb 23, 2019
    Posts: 118

    CPT_Kill_Roy
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    The one in the middle is very hard to find. NOS on eBay is all I could find.


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  14. southcross2631
    Joined: Jan 20, 2013
    Posts: 3,099

    southcross2631
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    Comp cams roller tip rockers are not that expensive and free up a few horses.
    ARP rocker studs are a good insurance policy. I ran the factory rockers on a solid lifter big block for years with nothing more than a poly lock.
     
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  15. Relic Stew
    Joined: Apr 17, 2005
    Posts: 1,117

    Relic Stew
    Member
    from Wisconsin

    The Ford setup has the same issues. The Boss 302 and Boss 351 had steel fulcrums instead of aluminum, so they work better with performance cams and spring pressures, but not easy to find today. If I upgrade a cam on a 351C or 460, I put in roller rockers as well.

    On a side note, I've read that the 351C was designed by an engineer who had previously worked at Oldsmobile. That's why it has the integral timing cover, 2 gallery oiling system and sled rocker design, just like an Olds engine.
     
  16. porknbeaner
    Joined: Sep 12, 2003
    Posts: 41,328

    porknbeaner
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    Neat trick but why? The Boss rockers are basically made from unobtainium and you can buy good roller rockers from several suppliers all day long from any catalog speed shop. granted they are going to be substantially stronger that the stamped steel ford rockers so maybe if you prefer flimsy over stout you would want the ford rockers.
     
  17. jaw22w
    Joined: Mar 2, 2013
    Posts: 903

    jaw22w
    Member
    from Indiana

    Ford rockers on a Chevy BBC??? Blasphemy!
     
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  18. George
    Joined: Jan 1, 2005
    Posts: 7,083

    George
    Member

    Reportedly the whole 351C/400/429 engine series were designed by engineers that came to Ford with Bunkie Knudsen. Some think the head chambers are similar to the BBC, with the BBC being similar to the Chr Polys.
     
  19. CPT_Kill_Roy
    Joined: Feb 23, 2019
    Posts: 118

    CPT_Kill_Roy
    Member

    I’m just trying to build things traditional. I know I can drop $300 plus on stainless steel roller rockers. I’m just reading old magazines and build up books from the 60s and 70s.
    Besides this board I have no one else to ask how things where done. My grandfathers are long gone.


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  20. CPT_Kill_Roy
    Joined: Feb 23, 2019
    Posts: 118

    CPT_Kill_Roy
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    I have that roller tip set up on my small journal 327, it got it that way.
    Can I run OEM long slot rockers with a poly lock? I wasn’t sure it would fit inside.


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  21. southcross2631
    Joined: Jan 20, 2013
    Posts: 3,099

    southcross2631
    Member

    My 396-375 Camaro that I bought new ran the original nuts until it became a weekly chore to adjust the valves set the timing and the dwell. I started using poly locks and it helped me go to a longer interval between valve adjustments. Could have had something to do with the daily 6500 through the gears.
    Replaced the nuts several times first though. Are you going to run solids or a hydraulic cam?
    One of my first updates was an L-88 cam and block the heat to the intake. The cam, headers and a decent shifter and traction masters took it from 14 flat at a 100mph. To a 12.80 at a 119mph. Then they had a ration of flywheel explosion's and all of the tracks made all solid lifter 4 speeds to install a scatter shield.
     
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  22. saltflats
    Joined: Aug 14, 2007
    Posts: 9,657

    saltflats
    Member
    from Missouri

    Installing 409 rocker arms would give you 1.75 ratio.
     
  23. Fordors
    Joined: Sep 22, 2016
    Posts: 2,298

    Fordors
    Member

    It's been a while and I might be mistaken but don't 348-409 rockers use 3/8's" studs? The BBC has 7/16" studs and the ratio is 1.72.
     
  24. MeanGene427
    Joined: Dec 15, 2010
    Posts: 1,378

    MeanGene427
    Member
    from Napa

    Yes the 69s had the double adjusting/jam nut setup, and they would not stay tight- I started taking car of my buddy's 69 in 74, and put poly locks on it, no more problems. That car is still 100% stock except for the poly locks and the factory recall pistons. The 70's that I've had apart all had the round pivot like the 429 and Chebbie. I built the engine for my other buddy's 70 in 79, and had Hannan's put 426 Hemi 5/16 stem tulip valves in it, and old road racer's trick that pumped up the bottom end a bit. Used the old 289 "Sullivan" cam with 8005-A springs. Still running and sounding great, in fact he drove it for several years with 2.75 gears in the rearend, and no problem getting around. You Bay Area boyz may recognize the Hannan's name
     
  25. saltflats
    Joined: Aug 14, 2007
    Posts: 9,657

    saltflats
    Member
    from Missouri

    Not all of the big blocks had 7/16 studs.
     
  26. CPT_Kill_Roy
    Joined: Feb 23, 2019
    Posts: 118

    CPT_Kill_Roy
    Member

    So far I’m planning to run a Solid lifter cam. Something close to the L88 cam. I have chrome valve covers with the drippers in them. Will the poly locks fit under the covers?


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  27. Deuces
    Joined: Nov 3, 2009
    Posts: 17,941

    Deuces
    Member
    from Michigan

    My 402 did..... ;)
     
  28. Every Big Block Chevrolet that I have seen had 7/16” studs.


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  29. saltflats
    Joined: Aug 14, 2007
    Posts: 9,657

    saltflats
    Member
    from Missouri

    Now that you guys mention it, not sure what I was thinking. Sorry, back to your schedule program. :oops:
     
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  30. southcross2631
    Joined: Jan 20, 2013
    Posts: 3,099

    southcross2631
    Member

    Is this going to be a race car or a street Gasser poser? There are so many better choices over the old L-88 cam . I ran a high compression 468 in an O/T 70 Chevelle SS with a .600 lift hydraulic cam that I shifted at 5800 and it ran IHRA super street. 7.00 1/8th mile.
    The car weighed 3750 with me in it. Used Comp gold roller rockers and never touched the valve lash except for between season tear downs. I had no more than about 2500 bucks in the whole motor. $50 marine block with crank. Stock rods with ARP bolts home ported oval port heads. Heavy but cheap TRW forged pistons. The motor had well over 500 documented passes before I sold it to another racer.
     
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