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Fitting a 454 in a '75?

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by LoggieStyle, Jan 27, 2003.

  1. LoggieStyle

    LoggieStyle Registered Member

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    Fitting a 454 in a \'75?

    Hello Everyone ,
    I'm in the middle of my first engine swap and I could use a little advice. I know people have done this swap plenty of times, but now that I have all the junk off the engine it looks like when I swap in my 454 for the old 350 the exhaust manifolds will either hit the frame or be directly above it. What do I need to do to avoid this? Any other advice on getting the engine to fit best would be appreciated also. I don't know if it makes a difference what year the engine is, but it's a '99 454 out of a Suburban.

    Thanks,

    Logan
     
  2. BlackDog714

    BlackDog714 1/2 ton status

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    Re: Fitting a 454 in a \'75?

    Get new motor mounts!
     
  3. Zeus33rd

    Zeus33rd Smarter than you GMOTM Winner

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    Re: Fitting a 454 in a \'75?

    I just swapped a big block into my '76 a couple months ago. Everything will fit just fine. You can even use the same motor mounts from the SB. It's just like swappin in another SB but alot heavier. /forums/images/graemlins/smile.gif
    Check out the little pic to the left...thats my Big Block. /forums/images/graemlins/thumb.gif
     
  4. OrangeCrushK10

    OrangeCrushK10 1/2 ton status

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    Re: Fitting a 454 in a \'75?

    Or, if you're really paraniod, you can always buy some block-hugger headers.

    But that's spending money and, as we all know, nobody likes that.
     
  5. Sandman

    Sandman 3/4 ton status Author

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    Re: Fitting a 454 in a \'75?

    You might have to get a set of headers or an older style of exhaust manifold. Not to sure if the newer trucks with the different frames had a different manifold. The whole thing should more or less be a bolt in. /forums/images/graemlins/grin.gif
     
  6. LoggieStyle

    LoggieStyle Registered Member

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    Re: Fitting a 454 in a \'75?

    Thanks for all the info, seems like either it should fit ok, or I might need to get some new mounts or headers which is no big deal.

    Thanks again guys,

    Logan
     
  7. BlackDog714

    BlackDog714 1/2 ton status

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    Re: Fitting a 454 in a \'75?

    When I say new motor mounts, its not cause they are different between SB or BB (or even diesel). Mine were so worn out, the mech fuel pump was 1/2 in away from the x/member!!! After the new mounts my headers fit perfectly and the was more than 4 in between the fuel pump and the x/member!
     
  8. KRAZIE87K5

    KRAZIE87K5 1/2 ton status

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    Re: Fitting a 454 in a \'75?

    Fits right in there "like a glove"! I used Hookers "super comp" headers... a little on the pricey side, but they dont contact the frame. If I had it to do over again, I would but STOCK EXHAUST MANIFOLDS, as headers are too damn hard to keep sealed up properly. I end up having to replce header gaskets once or twice per year. /forums/images/graemlins/tongue.gif

    -Dan
     
  9. Langosta39

    Langosta39 1/2 ton status

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    Re: Fitting a 454 in a \'75?

    I just put a '86 454 from a 1-ton in a '77 1/2 ton and the motor mounts were not even close. I had to get the mounts the motor mounts go on from the donor truck for it to work. Then the '77 motor mounts wouldn't bolt to the '86 x-member mounts since the newer ones are center hole mounts.

    I say there is no cut and dry, look at the donor and look at your truck, and measure before you have a 500lb engine hanging from your shop roof and no place to put it!

    andy
     
  10. KRAZIE87K5

    KRAZIE87K5 1/2 ton status

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    Re: Fitting a 454 in a \'75?

    You like hanging 500lb motors from your ceiling? Thats odd... I think my 454 was more in the 650-700lb range when it was bolted to my ENGINE HOIST... should try one of those some time... /forums/images/graemlins/rotfl.gif /forums/images/graemlins/eek.gif /forums/images/graemlins/thumb.gif

    -Dan
     
  11. Langosta39

    Langosta39 1/2 ton status

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    Re: Fitting a 454 in a \'75?

    OH! you mean they make those /forums/images/graemlins/wink.gif
    I didn't think they were that heavy either, hehehe.

    andy
     
  12. LoggieStyle

    LoggieStyle Registered Member

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    Re: Fitting a 454 in a \'75?

    I'll probably get some new mounts anyway, I am sure mine are shot. It seems all of you were able to get the engine to fit with a little work at most which is what I wanted to hear.

    And I think I'll try dangling the engine from my hoist, the closest thing I got to a roof is a basketball hoop.

    Thanks,

    Logan
     
  13. Brady

    Brady 1/2 ton status

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    Re: Fitting a 454 in a \'75?

    When you get the new mounts get the SB mounts.I put a 454 in a '79 Sub.I bought new BB mounts but they wouldn't work.The bolts holes are in different spots.So I used SB mounts for that year.The engine bolted right in.You will also need the BB acc. brackets and flexplate or flywheel.The 454s are externally balanced.I also used Dynomax headers for '73 to '87 trucks.Brady
     
  14. morphed86k10

    morphed86k10 1/2 ton status

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    Re: Fitting a 454 in a \'75?

    I just finished putting a 454 in my K10 last week so I'll give you some notes from what I just did.

    I kept all the accessories on the big block, just disconnected them, yanked the assembly, put it in the K10, and connected the lines. I swapped the K30 hydroboost system over at the same time, so I could use the PS pump on the big block.

    I had to get an externally balanced flywheel for the 454.

    I used the Small block motor mounts that were already in the truck, just replaced the rubber part with new urethane. YOU MUST TAKE THE BRACKETS OFF THE SMALL MOTOR and put them on the big block to drop it into place. Never, in my entire life, will I forget this fact. Or will I forget that the difference is not discernable to the eye at 2AM. But believe me, its there.

    I also swapped over the radiator at the same time.

    I had to take the distibutor off the big block to get adequate clearance while pulling it.
     

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