Engine mounts swap problems from 1970 350 to 455

Discussion in 'Race 400/430/455' started by aussiebuickv8, Jun 29, 2019.

  1. aussiebuickv8

    aussiebuickv8 Member

    Hi Guys I am doing and egine swap from a 350 to a 455, LeSabre Custom Convertible,
    Does anyone know what enigine mounts fit so as the new 455 can drop in.
    I tried 455 engine mounts and they dont seem to fit in the slot gap for the motor.
    Thanks for any info you can tell me in advance
    Darren from Australia.
  2. BrunoD

    BrunoD Looking for Fast Eddie

    I'm really not the expert here,but I know that you will need the mounts from a big car with a big block,as they are different then the small cars.So a Wildcat,La Sabre,even the Electra will fit,but not sure about this last one.You will have to measure modify the GS BBB to make it fit on your chassis.Bruno.
  3. 300sbb_overkill

    300sbb_overkill WWG1WGA. MAGA

    The sbb 350 frame pads won't bolt to the BBB motor mounts.

    You will also need the BBB frame pads for your swap from the year cars that have the same frame as yours.
    Mark Demko likes this.
  4. 455 Dirt Devil

    455 Dirt Devil New Member

    I believe your crossmember should have extra bolt holes beside the existing frame pads to mount for the big block configuration.

    Swapped a 1970 Buick 455 into a '74 Cutlass, and that's how I did it. I don't recall if I used the frame pads from the 1970 LeSabre, or just moved the pads from the original 350 Rocket. I do remember cranking all those bolts out, and didn't buy anything. Donor car was a '70 LeSabre Limited 4dr hardtop.

    The high compression version 455, 370 hp, from 1970 in that Cutlass made one helluva dirt car. It would still pass cars with just one wheel on the rear. Pulled so well off the corners, I had to look back from turn 3 to see where everyone went (still coming off turn 2), everything got so quiet, I couldn't hear the pack any longer. Didn't need to rev high, just let it pull in 2nd (automatic), with whatever rear gear the Cutlass came with (welded locker). Couldn't really hear my own car when the pack was close, since it wasn't screaming at high rpm.

    My first post here, looking forward to reading, if there's an introduction section I'll make a post there. Started out in a Buick, have owned several, and still have a newer one.
  5. Mark Demko

    Mark Demko Well-Known Member

    X2, did this years ago, had a '76 Electra with the 350, dropped in a 455, had to change mounting pads, and brackets.
    300sbb_overkill likes this.
  6. aussiebuickv8

    aussiebuickv8 Member

    Thanks buddy

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