454 (7.4L) swap / repair options - 1999 Suburban K2500

Discussion in 'Engine Performance + Maintenance' started by oifla, Sep 8, 2020.

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  1. Mangonesailor

    Mangonesailor I'm Awesome

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  2. b454rat

    b454rat I'm Awesome

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    Why the hell would you wanna build a tow motor, and make it a 427?!? Sorry but that’s fuckin stupid. 427s are a higher RPM motor, and hi RPMs are pointless when towing. If you do a basic rebuild on the motor, mild cam, and a good tune, it will wake it right up. Like I said before, I had a 97 with the 454, would smoke the tires from a stand still, and would pull like a dream. This was a 99.9% stock truck, think I had a K&N filter and true dual flows going out the back.
     
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  3. L29Sub

    L29Sub I'm Awesome

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    Thar's one thing that Chevy got mostly right. The exhaust on BB Vortec are right massive.

    Sent from my SM-G965U using Tapatalk
     
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  4. Christian Steffen

    Christian Steffen I'm Awesome

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    Comp sells a conversion stud to run standard big block rockers with the vortec heads.

    https://www.summitracing.com/parts/cca-4514-kit
     
  5. Christian Steffen

    Christian Steffen I'm Awesome

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    So I remember reading that FSC thread back in the day.. was he claiming whp/wtq or flywheel? The HP seems quite reasonable at flywheel, the torque sounds inflated to me but i could be wrong. The 493/609 with some boost sounds perfectly reasonable IMO.
     
    Last edited: Sep 17, 2020
  6. badco

    badco I'm Awesome

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    When i go back to the shop ill post some numbers from a 402 head
     
  7. badco

    badco I'm Awesome

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    427 holds together better, rod angle is better and it has a really broad rq curve compared to 454 having a big jumo then dip in tq. They didn't make a tall deck 454 for heavy duty and did a 427... ever wonder why?
     
  8. badco

    badco I'm Awesome

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    The reason the performance 427 was considered a rpm engine was the power was made up high because of the rectangle port heads. The rectangular port heads flowed massive air and hurt bottom end alot
     
  9. badco

    badco I'm Awesome

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    The conversion ones work but thats were weak point will be. Only option if heads are still on engine
     
  10. b454rat

    b454rat I'm Awesome

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    The 427 tall deck had a heavy ass rotating assembly, really only the pistons but had a huge flywheel too, that translates to torque. I’ve never heard anybody build a 427 for torque. The heads sucked on TDs, maybe cause a 454 needs more air they opted not to build one.
     

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