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Small block to big block swap

Discussion in 'The Garage' started by stylin6, Jul 27, 2002.

  1. stylin6

    stylin6 Registered Member

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    Does anyone know if the crossmember/towers were the same for the small blocks and big blocks in the 73-77 Suburbans? I assume swapping in a big block should be a direct bolt in, or am I mistaken??
     
  2. Yukon Jack

    Yukon Jack 1/2 ton status

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    I know the towers for 67-72 2wd big block are different than the small block towers. I believe the same is true for the 73-and up.

    I'm preparing to do a big block swap into my 69 and so far everyone has told me to use my small block mounting parts, just moved forward. Are you looking for big block towers?
     
  3. 1 FN HI K5

    1 FN HI K5 1/2 ton status

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    Let me know how it goes im going to do this swap also 1997 454 in my 72.. <font color="red"> 1 FN HI K5 </font color>
     
  4. Brady

    Brady 1/2 ton status

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    In the 73 and up the BB will bolt right up to the SB mounts.No need to move or anything.You will need all the accesories for the BB.You will need to modify the exhaust.Should go bigger tube.Also you will need a 4 core radiator.A 3 core won't keep it cool enough.Also the 454 is externaly balanced so the 350 flywheel or flexplate won't work.
     
  5. stylin6

    stylin6 Registered Member

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    Well, I finally got the SOB in there (a lot tougher than the old smallblock conversion)!!! The towers worked fine- I went ahead and used the smallblock motor mounts also because the big block mount holes were a little too wide (the mount itself is the same size). Since this suburban is a 70 on a 77 frame, I had to hammer a couple small dents into the firewall to get it to miss the valve covers. I think the body is a little further forward on the frame than it would have been if it were still on the original frame.

    By the way, make sure you've got a couple of guys to help you drop the motor in- these bad boys are HEAVY!!!
     

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