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small block to big block

Discussion in 'Chevy Trucks' started by jlsanborn, Jun 20, 2003.

  1. jlsanborn

    jlsanborn Member
    Messages: 34

    I'm fixin to yard out the 350 in my '77 and install a 454 out of a '75 C20. Is this thing going to bolt in or do I have to modify the motor mounts?
     
  2. Rick Loncosky

    Rick Loncosky Senior Member
    from 17557
    Messages: 102

    I can help you out with this. It's a direct bolt in. Just remember you need the flex plate / flywheel, power steering pump & bracket and the alternator bracket w/ pulleys. If you get the engine complete you'll have it made. Rick
     
  3. jlsanborn

    jlsanborn Member
    Messages: 34

    Thanks Rick,
    One area of question would be the power steering pump. My K30 has the hydra-boost brake assist. The C20 is vacuum. Is the pump for the hydra setup different? Higher volume? Higher operating pressure? Without knowing for sure I would prefer to keep the pump/booster together. It dose'nt look like the brackets are the same.
     
  4. Mike 97 SS

    Mike 97 SS Banned
    from U.S.A.
    Messages: 1,106

    Do me a favor and get rid of that nasty looking avatar you have. Why not have something nice for our eyes to look at, maybe a nice lookin girl or a set of hooters, or even a plow truck. What you have is horrible. By the way, welcome to PlowSite. Mike
     
  5. Rick Loncosky

    Rick Loncosky Senior Member
    from 17557
    Messages: 102

    I'm not certain of pump pressure on those set ups. I wouldn't know why you couldn't use the BBC power steering bracket & your current pump assembly, that's if they mount up the same. You'll have to check your pulley alignment when your complete. I'd try to scarf the radiator, alot of the times they run 3 or 4 rows. I'm in Tenn. & Kentucky. next week, when I return I have a BBC pump that I can measure from the front of the pump to Center Line of pulley and maybe we can figure this out if it'll work.
     
  6. Rick Loncosky

    Rick Loncosky Senior Member
    from 17557
    Messages: 102

    I asked a local Chevy guru and he believes the power steering pumps are the same for the hydro boost braking system & regular power steering. Can you do a side by side comparison for 100% verification? Hope this helps. Rick................
     
  7. jlsanborn

    jlsanborn Member
    Messages: 34

    I will be knee deep in the engine compartment tomorrow. I will have a closer look.
    Anyone know if the clutch is different for the 454?
     
  8. Rick Loncosky

    Rick Loncosky Senior Member
    from 17557
    Messages: 102

    You'll need a 454 flywheel. A 396/427 flywheel is internally balanced and the 454 is externally balance. The pressure plate & clutch disc are the same for small blocks & big blocks. Go for it!
     
  9. jlsanborn

    jlsanborn Member
    Messages: 34

    had a closer look at the pumps. The only difference I can see is the reservoir capacity. I will run the pump off the ol 350.