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.

How do you like your big block?

Discussion in '1936-Present Suburban' started by stylin6, Jun 13, 2002.

  1. stylin6

    stylin6 Registered Member

    Joined:
    Apr 1, 2002
    Posts:
    40
    Likes Received:
    0
    Location:
    Kansas
    Thinking about dropping a 454 into my 70 Suburban. I'll be using it a lot for towing and some wheeling. How do you all like your big blocks? Am I looking at breaking about 7MPG on the interstate??? /forums/images/icons/smile.gif
     
  2. lugnut

    lugnut 1/2 ton status

    Joined:
    Aug 3, 2001
    Posts:
    268
    Likes Received:
    0
    Location:
    North Carolina
    I have a 454 in my 78 it gets about 9 mpg towing or not. I have 3.73 gears and run 33s on it. I love it!!
     
  3. Ddragggon

    Ddragggon 1/2 ton status

    Joined:
    Apr 25, 2001
    Posts:
    2,657
    Likes Received:
    0
    Location:
    Hartford, WI (formerly Etiwanda, SoCal)
    I have a 77 3/4 ton 2 wd suburban, with highway gearing in the rear, and it pulls 13 MPG regardless of speed, towing, loaded, or empty and more importantly, you don't lose any speed going up long mountainous hills. I'd never trade it for a small block. I've beaten ricers while hauling a loaded car hauler behind me, and absolutely love the sound of a bigblock roaring through glaspacks in the I-10 Deck tunnel.

    do it. do it now.

    -Rich
     
  4. stylin6

    stylin6 Registered Member

    Joined:
    Apr 1, 2002
    Posts:
    40
    Likes Received:
    0
    Location:
    Kansas
    Do you guys have any idea if you've got to change the motor mount towers to get the big block in the truck?
     
  5. 91K5

    91K5 1/2 ton status

    Joined:
    Jul 5, 2000
    Posts:
    185
    Likes Received:
    0
    Location:
    Wichita, Kansas
    Go for it! My dad used to have a '76 C20 with a 454 and it got 7MPG no matter what. Whether it was empty driving around town, or had the camper and a boat behind it doing 70 down the highway, it always got 7MPG. I have a 402 BB in my '72 Chevelle and theres nothing like the torque, I have 2.73:1 gears and can light em up for 30 feet from a dead stop /forums/images/icons/shocked.gif Now that I'm done ranting you probably wont need big block mount towers, I've only done 1 small to big block swap where I needed big block motor mounts.
     
  6. stylin6

    stylin6 Registered Member

    Joined:
    Apr 1, 2002
    Posts:
    40
    Likes Received:
    0
    Location:
    Kansas
    Outstanding! To tell you the truth, I'm tempted to drop the 454 in my Camaro, but need it in the Suburban for towing. Maybe when I win the lottery!
     
  7. chvyhs

    chvyhs 1/2 ton status

    Joined:
    Feb 12, 2001
    Posts:
    1,469
    Likes Received:
    0
    Location:
    Murrieta, California
    My big Block

    That's how I like my big block. I went from an inline 6 to a small block. When I went from the small block to the big block I didn't have to change the motor mounts or the motor mount brackets (on the frame). My uncle uses his BB dually to tow a 30' trailer to the track. I was following behind him once and I was having trouble keeping up with him. You gotta love that torque on demand.
     
  8. stylin6

    stylin6 Registered Member

    Joined:
    Apr 1, 2002
    Posts:
    40
    Likes Received:
    0
    Location:
    Kansas
    Well, I took the big jump and got the block. Now its time to build it and drop her in!
     
  9. Ddragggon

    Ddragggon 1/2 ton status

    Joined:
    Apr 25, 2001
    Posts:
    2,657
    Likes Received:
    0
    Location:
    Hartford, WI (formerly Etiwanda, SoCal)
    Sweet! choose your Cam wisely... the biggest gain in power your engine will see will come from your initial cam selection. some better-than-stock heads will help, but having a good bumpstick is what'll bring the bastard to life.

    -Rich
     
  10. four_by_ken

    four_by_ken 1/2 ton status

    Joined:
    Jun 9, 2001
    Posts:
    3,806
    Likes Received:
    0
    Location:
    Allenton, MI
    Since I tow with my Suburban, I wouldnt do anythign but a 454 in it. Wouldnt even think of a small block. Heck, even if I didnt tow I wouldnt do anything but a big block. And gas mileage is not much worse since the motor is not in a constant struggle.

    Ken H.
    '85 Suburban - 3/4 ton - Detroit rear - 4.10 - 454 - 400 trans - 33 muds
     
  11. Ddragggon

    Ddragggon 1/2 ton status

    Joined:
    Apr 25, 2001
    Posts:
    2,657
    Likes Received:
    0
    Location:
    Hartford, WI (formerly Etiwanda, SoCal)
    I actually get better mileage in my suburban with the 454 then my friend does in his with the little 350.... the gearing is pretty close to the same, but I get 13, and he gets 8. the reasoning for this, is the 454 creates more torque initialy then the 350 ever does, making it so I don't have tu burry my foot in the accelerator to make my truck move. he has to almost floor it to make his leave a stoplight ( part of his problem is he's running 31x10.50's on a 2wd, where it was meant to run littler tires... 235/75-15's) where I can out accelerate him at an off idle speed ( even when I was running 33's under it)

    -Rich
     
  12. muddysub

    muddysub 1 ton suburban status Staff Member Moderator GMOTM Winner

    Joined:
    Jun 23, 2001
    Posts:
    10,451
    Likes Received:
    489
    Location:
    my garage, Henderson, NV
    wow better miileage with a big block? i didn't know that was possible. /forums/images/icons/shocked.gif /forums/images/icons/cool.gif
     
  13. Ddragggon

    Ddragggon 1/2 ton status

    Joined:
    Apr 25, 2001
    Posts:
    2,657
    Likes Received:
    0
    Location:
    Hartford, WI (formerly Etiwanda, SoCal)
    all you gotta do is get your carb dialed in right, have a better-then-stock cam in it, and enjoy. like all BBC's, mine gets 12-13 regardless of uphill, downhill, loaded, empty, hauling a trailer, or racing people on the freeway at 95 MPH. if I keep it at high speeds for a long time, I notice it dropping down to 10, but it stays in that general range of mileage

    -Rich
     
  14. muddysub

    muddysub 1 ton suburban status Staff Member Moderator GMOTM Winner

    Joined:
    Jun 23, 2001
    Posts:
    10,451
    Likes Received:
    489
    Location:
    my garage, Henderson, NV
    cool, what about EFI? could the same be said about a tbi or mpfi 454?
     
  15. four_by_ken

    four_by_ken 1/2 ton status

    Joined:
    Jun 9, 2001
    Posts:
    3,806
    Likes Received:
    0
    Location:
    Allenton, MI
    Adding fuel injection will bring up the mileage and power of just about any motor, plus response, everything.

    A big block will get better mileage sometimes because it is not working as hard as a small would be pulling a load or just lugging around a big Suburban.

    I like having big blocks in both my Blazer and Burban. wouldnt go any other way.

    Ken H.
     
  16. stylin6

    stylin6 Registered Member

    Joined:
    Apr 1, 2002
    Posts:
    40
    Likes Received:
    0
    Location:
    Kansas
    I finally got that big 468 put in the beast. Put a TH400 behind it along with a NP241 transfer case. Got rid of the 305/350/203 piece of junk that was in there. The power is great- Now for the axle upgrades!!!

    Anybody out there got any 70 Suburban parts? I need a good set of barn doors for mine.
     
  17. mountainexplorer

    mountainexplorer 1/2 ton status

    Joined:
    Nov 14, 2001
    Posts:
    4,903
    Likes Received:
    0
    Location:
    Spokane, Wa./Ione, Wa
    I have a mildly built 454 in my Suburban (dropped it in last year to replace the 350). Tows pretty good. Still havent gotten accurate figures on gas mileage yet.

    I also have a stock 454 in my 81 Crew cab w/4.10 gears and 35's. It gets about 7 mpg towing or not. Not much on acceleration, but it always gets the job done.

    The built 396 in my other Crew Cab will break loose the 40" tires on pavement. Gets no better than about 5 mpg though on the highway.
     
  18. thatK30guy

    thatK30guy 1 ton status Premium Member

    Joined:
    Jan 12, 2001
    Posts:
    32,076
    Likes Received:
    55
    Location:
    .
    I like my mildly built 454 in my K30. Got enough power to do this and that, but the 5 to 7 mpg really takes the thrill out of going to the gas station quite a bit. /forums/images/graemlins/frown.gif

    BTW, where in Kans-Ass are you? I'm in central part, 35 miles west of Salina.
     
  19. afroman006

    afroman006 1/2 ton status

    Joined:
    Aug 21, 2002
    Posts:
    2,876
    Likes Received:
    0
    Location:
    College Station & Kingsville, Texas
    I think this has been asked before but I have yet to see a clear answer. If you install a TBI 454 into a previously TBI 350 truck (Burban in my case), will the original puter still work, will I need a completely new one, or will I just need a new chip (Is a chip cheap or easy to install?)? My dad gave me a 454 2 bolt short block and I want to build it into a thumper. /forums/images/graemlins/thumb.gif. Maybe its just me but I think the size of Sub's and K30's neccessitates BIG BLOCKS!!! /forums/images/graemlins/eek.gif
     
  20. Stephen

    Stephen 1/2 ton status Moderator Vendor

    Joined:
    Sep 15, 2000
    Posts:
    4,227
    Likes Received:
    142
    Location:
    Carbondale Colorado
    How about gearing-transmission-lift-tire combos with some of these subs that run over 10 mpg? I'm looking at adding a 454 to my crewcab instead of the 6.2TD for the broad torque range and greater output but I too am not very excited about mid single digit milage when running empty. I'm also not very encouraged by the report on the stock 454 with 4.10's and 35s being kind of a dog. That's not far off from what I'm going to have......
    I've considered a gearvendors overdrive but am not too happy with $2400.00 up front just to get better milage. $2400 buys me a lot of gas, and I don't have to do it all at once. Of course splitting gears in the TH400 might be nice with Wally on the trailer.
     

Share This Page