Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

73 und up..are the motor mounts the same as 67-72 trucks? also fitment

Discussion in '1969-1972 K5 Blazer | Truck | Suburban' started by supersize75k5, Aug 18, 2004.

  1. supersize75k5

    supersize75k5 OrganDonorRacing.com

    Joined:
    Feb 3, 2004
    Posts:
    8,832
    Likes Received:
    4
    Location:
    gilbert az
    I have decided to put my 454 in the 72 for now, but I have no motor mounts, are 67-72 mounts different from my mounts for 73-91?

    If so how much are mounts for these trucks, I am seeing most parts are not cheap for them /forums/images/graemlins/grin.gif


    Also any fitment issues with the big block? Didn't some of these trucks come with them?

    thanks for all the help /forums/images/graemlins/thumb.gif
     
  2. Yukon Jack

    Yukon Jack 1/2 ton status

    Joined:
    Jul 25, 2002
    Posts:
    1,984
    Likes Received:
    0
    Location:
    Rose Hill, KS
    The 67-72 years did not come with a big block. I just finished putting a big block in my 69 K20 and had to modify the firewall even with a body lift. Some people get them in without having to modify the firewall, some have to do a little massaging, not sure why that is.

    An easy way is to move the engine forward. I would guess 1 1/2 to 2" would be plenty but I do not know the exaxt measurement for a fact. If you look in some older posts on this forum you will see my posts about fitting the big block. Will be in May and June.

    You can use the later crossmember and mounts. In fact that is supposed to be better cause you can fit headers easier. If you will pm me your e-mail address I will send you an article on that. Burt4x4 is trying this approach presently.

    Here is my 454 in the stock small block location using the stock crossmember and engine mounts.

    [​IMG]

    Be happy to help answer any more questions you have.
     
  3. Burt4x4

    Burt4x4 3/4 ton status

    Joined:
    Feb 17, 2000
    Posts:
    6,854
    Likes Received:
    0
    Location:
    California (Modesto area)
    Yup I am smak dab in the middle of doing this:
    [​IMG]

    The first gen crossmember goes directly under the oil pan and will not alow you to drop the oil pan with out lifting the engine and/or removing the crossmember. By puttin in a 73+ crossmember and frame mounts you can now remove the oil pan with no issues. Headers are suppose to have more clearance as well.
    GM did make a 454 only crossmember but this is not the one you want, mounts are way more expensive and the 454 only crossmember and mounts are harder to find. The artical above is using SBC crossmember. The SBC & BBC mounts are the same bolt pattern and are the same distance from the bell housing, gotta love GM /forums/images/graemlins/thumb.gif
    To get the 73+SBC crossmember to mount up you will need to drill new holes int he frame rail but according to the artical the back two original crossmember holes are used as a 'starting point' for the new crossmember's location. I decided to wait on drilling until I get the BBC inplace just to varify were the holes need to be drilled.
    Hope this helps
    Burt
     
  4. stretch67

    stretch67 1/2 ton status

    Joined:
    Nov 1, 2003
    Posts:
    171
    Likes Received:
    0
    Location:
    bozeman mt
    actually they did put big blocks in those trucks! 1972 for sure 71 i think also.2 wheel drive only though, 3/4 tons only. they used the 402 (30 over 396) a buddy of mine picked up a 72 gmc camper special with 28000 original miles,factory rat,ac,tach,tilt column with all the chrome 2500 bucks that bastard!!! as far as firewall room on 2wd trucks i am not sure on big block i moved mine forward 2-3"s on my 4x4 67. another buddy has a 70 gmc and his distributor to firewall room is 3 inches with the stock small cap no hei fit no problem! /forums/images/graemlins/thumb.gif
     
  5. Burt4x4

    Burt4x4 3/4 ton status

    Joined:
    Feb 17, 2000
    Posts:
    6,854
    Likes Received:
    0
    Location:
    California (Modesto area)
    Yes you are correct, the 2x4 did have a 396/402.The crossmember and engine mounts are differnt on the origianlly equip BBC trucks. Greg72 has a 396 in his 72 K5 and the firewal did need to be 'massaged' a lil bit. I too plan on whipping out the BFH and WACK WACK. /forums/images/graemlins/yikes.gifhehehehe
    Can't wait to drive my K5 again
    YYYYYYYEEEEEEEEEEHHHHHHHHHHHHHHHHHAAAAAAAAAAAABBC!!!
     
  6. stretch67

    stretch67 1/2 ton status

    Joined:
    Nov 1, 2003
    Posts:
    171
    Likes Received:
    0
    Location:
    bozeman mt
    just one tip /forums/images/graemlins/shame.gif wait to paint the firewall till after you beat it with a BFH! mine now has black undercoating where the nice paint was! /forums/images/graemlins/hack.gif /forums/images/graemlins/hack.gif /forums/images/graemlins/hack.gif
     
  7. Burt4x4

    Burt4x4 3/4 ton status

    Joined:
    Feb 17, 2000
    Posts:
    6,854
    Likes Received:
    0
    Location:
    California (Modesto area)
    hahaha...too late. I tend to drink beer in my garage and after a wile I start hearing a lil voice comming from my spay can collection..."Paint Me" "Spray Me".... /forums/images/graemlins/screwy.gif SO I do most my painting under the influance /forums/images/graemlins/doah.gif /forums/images/graemlins/histerical.gif
    No worries I have more paint and more BEER /forums/images/graemlins/whistling.gif /forums/images/graemlins/weld.gif /forums/images/graemlins/hack.gif /forums/images/graemlins/grind.gif /forums/images/graemlins/histerical.gif
     
  8. stretch67

    stretch67 1/2 ton status

    Joined:
    Nov 1, 2003
    Posts:
    171
    Likes Received:
    0
    Location:
    bozeman mt
    i see you have the front sheetmetal off burt, thats the time to do the motor-crossmember swaps. which brings up tip#2 /forums/images/graemlins/shame.gif note to self don't put 6 inch lift on truck then do crossmember swap that requires installing and removing 700 lb engine 15 times after truck is painted and put together /forums/images/graemlins/doah.gif never said i was smart just optimistic! oh if you are still looking at motor mounts the ORD ones are very good! they work for small and big blocks! /forums/images/graemlins/hack.gif web page
     
  9. Burt4x4

    Burt4x4 3/4 ton status

    Joined:
    Feb 17, 2000
    Posts:
    6,854
    Likes Received:
    0
    Location:
    California (Modesto area)
    hahahah Noted /forums/images/graemlins/thumb.gif
    Ya I got the ORD stuff. Thoes orginally equipt BBC trucks cannot use the ORD Engine Mounts. The orginal BBC mounts at the frame rail are in a V instead of an L pattern like the SBC stuff. Look at that artical I posted and the last pic in the artical on the left you can see the mounting holes, 3 of them, make an L shape. When I was researcing this I found out that the OE BBC mounting plates have a V bolt pattern and won't work with the ORD mounts..
    Fun Stuff /forums/images/graemlins/peace.gif
     
  10. Yukon Jack

    Yukon Jack 1/2 ton status

    Joined:
    Jul 25, 2002
    Posts:
    1,984
    Likes Received:
    0
    Location:
    Rose Hill, KS
    [ QUOTE ]
    actually they did put big blocks in those trucks!

    [/ QUOTE ] Yep, you are correct, I meant to say not in the K series in 67-72.
     
  11. Triaged

    Triaged 1/2 ton status

    Joined:
    Feb 21, 2001
    Posts:
    3,808
    Likes Received:
    0
    Location:
    CA (LA/OC area)
    I posted up the part #'s a while back. Energy Suspension doesn't make them...ProThane? does.

    They are NOT the same as 73-up (or any other GM motor mount for that matter!) They are around $60 from summit.
     
  12. supersize75k5

    supersize75k5 OrganDonorRacing.com

    Joined:
    Feb 3, 2004
    Posts:
    8,832
    Likes Received:
    4
    Location:
    gilbert az
    thanks you guys! If I get my air compressor going I might get the frame done and have the big block it in by next weekend!

    This weekend is all about the 86 though /forums/images/graemlins/pimp1.gif
     
  13. R72K5

    R72K5 Banned

    Joined:
    Mar 5, 2001
    Posts:
    8,905
    Likes Received:
    0
    Location:
    central IL
    [ QUOTE ]
    actually they did put big blocks in those trucks! 1972 for sure 71 i think also.2 wheel drive only though, 3/4 tons only. they used the 402 (30 over 396) a buddy of mine picked up a 72 gmc camper special with 28000 original miles,factory rat,ac,tach,tilt column with all the chrome 2500 bucks that bastard!!! as far as firewall room on 2wd trucks i am not sure on big block i moved mine forward 2-3"s on my 4x4 67. another buddy has a 70 gmc and his distributor to firewall room is 3 inches with the stock small cap no hei fit no problem! /forums/images/graemlins/thumb.gif

    [/ QUOTE ]

    68 was the first year for big block GM trucks
    68 69 were 396, 70-72 were 402(marketed as the 400 at the counter)


    and you are wrong on 3/4 ton only statement,

    big block engine option was available for all 10-series and 20 series and 30 series 68-up

    and in the 2wd K5's i forgot if you could get a BBC in them or not, ill have to look again



    2wd though, not 4x4 until later years

    i know of a 67 K10 that was in town for a couple years from OH and the guy put in a 454 and new th400 and a 203 out of a 70s blazer and he didnt have to clearance for the HEI

    some you have to, it depends on if the truck is factgory v8 or straight six, theres two sets of holes, one set for each engine design,
    if was a 292 truck then it will be more involved
    one engine mount is about 3" further forrward than the othjer with 292, i think its the pass side,
    and in the 63-72 trucks that frame tree bracket is unique just for those trucks and just for those engines i had one i threw it away last fall finally along with alot of other 63-72 mounts and bracketgs and pullies and alt setups and ram horn manifolds and such, several truck loads of 10 years of disassembly of 67-72 trucks went to shredder one day, could not find new homes for anymore, got tired of trying


    good luck
     

Share This Page