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.

Big block build and transmission options

Discussion in 'The Garage' started by Jagged, Apr 1, 2007.

  1. Jagged

    Jagged 1 ton status

    Joined:
    Apr 25, 2005
    Posts:
    11,460
    Likes Received:
    1
    Location:
    SWVA
    I'm building a big block for my '89. 454, .040 over, 427T heads, just under 9:1 compression, and crane's truck cam for idle-4600 (.485/.485 266/266@.050").

    Right now the truck has it's original 700R4. I can rebuild the 700R4 using the tightest tolerances, but I really don't think it will last. I'll be running 3/4 ton axles with 3.73's. With 31-33" tires my rpms at 65 MPH on another transmission (TH350/TH400/SM465/etc) with a 1:1 final drive is from 2628-2469 RPM. With overdrive, I'm only turning 1802 RPM.

    So, we're looking at almost a 1,000 RPM difference between overdrive and a 1:1 final.

    Basically, I want to drive 65-70 MPH without my 454 sounding like it's gonna explode. Thoughts, comments, suggestions?
     
  2. Chevy305

    Chevy305 6 Lug 14bsf Status Premium Member GMOTM Winner

    Joined:
    Jan 23, 2006
    Posts:
    11,228
    Likes Received:
    485
    Location:
    New Hampshire
    go 465 and never look back!
     
  3. 76zimmer

    76zimmer Flyin Rat Premium Member GMOTM Winner

    Joined:
    Nov 14, 2005
    Posts:
    23,031
    Likes Received:
    1,347
    Location:
    Kzoo, Mi
    I really don't know why people think 2800 rpm is excessive, most of these engines dont make max torque until close to 4000 or more. If your only running 26-2800 it would be perfect cruising range. Maybe not real great on gas, but if your running a BB that shouldn't be a concern anyway.
     
  4. Chevy305

    Chevy305 6 Lug 14bsf Status Premium Member GMOTM Winner

    Joined:
    Jan 23, 2006
    Posts:
    11,228
    Likes Received:
    485
    Location:
    New Hampshire
    X2...

    My 305 will cruise around at 3250 rpm all day long.
     

Share This Page