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.

Stock 350 TBI fuel pump enough for 454TBI motor?

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by fortcollinsram, Oct 15, 2002.

  1. fortcollinsram

    fortcollinsram 1/2 ton status

    Joined:
    Nov 8, 2001
    Posts:
    2,261
    Likes Received:
    0
    Location:
    Fort Collins, CO
    I am going to be doing my 350tbi to 454 tbi swap in the near future and I am trying to work out all the logistics (BEFOREHAND, for once) so my truck has minimal down-time...I have the 454 TBI motor and I am going to be installing a new cam/lifters, new timing chain, etc...Just freshening it up a bit...Do you guys think I will have to replace the 350 TBI fuel pump with a bigger one? I have the fuel pump for the 454 but I really, really, really, really don't want to have to drop the tank and replace it...If the stock one (for the 350) isn't enough, could I just add an in-line fuel pump deal to take up the exta slack...I figure that Cummins have 2 fuel pumps, why can't I So what do you guys think...



    Chris
     
  2. 3car

    3car 1/2 ton status

    Joined:
    Dec 16, 2001
    Posts:
    976
    Likes Received:
    0
    Location:
    Hernando, Florida
    350 tbi pump will be fine. /forums/images/graemlins/thumb.gif
     
  3. captain chaos

    captain chaos 1/2 ton status

    Joined:
    Mar 29, 2002
    Posts:
    413
    Likes Received:
    0
    Location:
    dickinson, north dakota
    just went threw this issue, this spring.
    if you are adding after market part's to the 454, STOCK 454 pump will not be enough.
    a STOCK 454 pump is barly big enough to run the 454 and under certain condition's isn't big enough for that.
    i put pump's from a tuned port corvette in mine and cured all my problem's.
    i do still have the gm part number's here if you need them.
    pm me if you need them.

    dave
     
  4. 3car

    3car 1/2 ton status

    Joined:
    Dec 16, 2001
    Posts:
    976
    Likes Received:
    0
    Location:
    Hernando, Florida
    if you put a tpi pump in,why didnt you mention how you regulated the fuel pressure?seems like pertanant information,being that tpi is ran at a much higher pressure than tbi.a 350 tbi pump will have no problem with a tbi 454 engine.a 350 and 454 pump run the same pressure,but the 454's injectors flow more.count on that.rob
     
  5. fortcollinsram

    fortcollinsram 1/2 ton status

    Joined:
    Nov 8, 2001
    Posts:
    2,261
    Likes Received:
    0
    Location:
    Fort Collins, CO
    Well, both pumps may be capable of the same ABSOLUTE pressure, but are they both rated at the same gph, or flow-rate? Somebody tell me that they are pretty damn close cuz I really don't want to dro pthe fuel tank...And wouldn't the stock fuel press. regulator take care of the TPI pump's high pressure...doesn't the reg. just direct unused fuel back to the tank....


    Chris
     
  6. HarryH3

    HarryH3 1 ton status Author

    Joined:
    May 31, 2000
    Posts:
    10,384
    Likes Received:
    2
    Location:
    Georgetown, TX
    The 350 and 454 pumps may produce the same pressure, but at what volume? The flow rating at a given pressure is important, as a 454 at 5,000 RPM will need a lot higher volume of fuel than a 350 at 5,000 RPM.
     
  7. 79Silv4x4

    79Silv4x4 Registered Member

    Joined:
    Aug 14, 2002
    Posts:
    50
    Likes Received:
    0
    Location:
    Lawton, OK
    Just taking a '90 pickup for an example, the Delco replacement pump listed is the same part number for the 454 and the 350.
     
  8. fortcollinsram

    fortcollinsram 1/2 ton status

    Joined:
    Nov 8, 2001
    Posts:
    2,261
    Likes Received:
    0
    Location:
    Fort Collins, CO
    So instead of dropping the tank and going through all that rigamaroll, could I just add a little in-line pump to take up the extra slack?

    Chris
     
  9. HarryH3

    HarryH3 1 ton status Author

    Joined:
    May 31, 2000
    Posts:
    10,384
    Likes Received:
    2
    Location:
    Georgetown, TX
    That's good info! /forums/images/graemlins/cool.gif So the pump for the 350 is over rated, probably so GM has to keep one less part number in stock. /forums/images/graemlins/wink.gif
     
  10. Chris Demartini

    Chris Demartini 1/2 ton status

    Joined:
    Feb 17, 2000
    Posts:
    2,406
    Likes Received:
    1
    Location:
    Dumont NJ 07628
    <font color="blue">I vote for dropping the tank. I had the 31 out of my 89 in about an hour, and thats with the skidplate too
     
  11. 3car

    3car 1/2 ton status

    Joined:
    Dec 16, 2001
    Posts:
    976
    Likes Received:
    0
    Location:
    Hernando, Florida
    79,im glad you mentioned that,i thought they would be the same part#,but i didnt want to open my yap till i was sure.i do know that a buddy has dont the swap twice with no probs.if there was fuel starvation,you would know.rob
     
  12. captain chaos

    captain chaos 1/2 ton status

    Joined:
    Mar 29, 2002
    Posts:
    413
    Likes Received:
    0
    Location:
    dickinson, north dakota
    i regulated the fuel pressure with turbo city's regulater that came with there tbi. /forums/images/graemlins/cool.gif

    dave
     

Share This Page