ZZ427 , ZZ454 , or ZZ502

Discussion in 'Engine Topic' started by Peter Wilson, Mar 27, 2011.

  1. Peter Wilson

    Peter Wilson Veteran Member

    I need Opinions ! I am in the process of converting my '71 Z/28 from a racecar into a street car , the car has 11,000 original miles and was tubbed in '72 and run as a Legal SS/IA racecar from '72 to '84 , then was converted to a modified production car with a roller cammed LS-6 454 . the engine was hurt in '89 and the car sat in a garage since then . the damaged LS-6 was sold out of the car around 2005 , I bought the car in 2006 and have been collecting parts ever since . my intentions were always to go back bigblock . what would be the best all around street crate engine for this car , the GMPP 427 , 454 , or 502 . I have always loved screamers , but torque monsters are good too . I just dont want to tear the car apart with a torque monster . I have been leaning towards the 427 , but the 502 seems to have a better crank and heads , ( GMPP catalog states the 502 crank is cross-drilled , heads are basically the same except the 427 has 2.19 intakes compared to the 502 having 2.25s ). This car has a turbo 400 and 9" Ford rear with drag axles and spool . Iam changing the axles to street axles , a 4.11 gear and a detroit locker , the auto transmission might stay for the first summer , but I have rebuilt an M-22 to go in the car eventually . The turbo 400 has an L-88 convertor , I took out the "as-raced " Turbo 400 w/manual valve body and 5500 stall converter and sold it off as it would never be used by me anyway as I dont think this car will ever see the track again . I need opinions on what would be the best engine . the 502 and the 427 are real close , price wise , the 454 is a bit cheaper . I also want to have an engine with "room to grow " in case I want to go more radical later
    Last edited: Mar 27, 2011
  2. Kamaro

    Kamaro Veteran Member

    Oct 31, 2010
    Stay away from any of these "low tension piston rings" engines from GM, they are prone to excessive oil consumption, if I'm out for a big block, I would start with a stout short block and start from there, picking the best pieces that suite my budget.
  3. ZS10

    ZS10 Moderator Staff Member Lifetime Gold Member

    Jan 18, 2003
    BC, Canada
    Can't say what the best for you, and your style and conditions that you drive in, but for me, I like my 427/4L80 Makes lots of power for street use, and I would never consider a non-overdrive trans.
  4. andrew1977

    andrew1977 Veteran Member

    Oct 1, 2006
    parksvegas, BC
    i put a zz502 in my dads car, does go through a little oil... doesn't smoke or anything though.

    took awile to tune it well with the carb that came with it, but the car now runs great and can be driven daily. we have and do drive it two hours to the drag strip and two hours back.

    with bad 60' times it ran a 11.70, full weight 1980 camaro (all steal body panels, full interior). with 125 shot of nitrous it ran an 11.22 @122 with a bad 60' time and running out of gear well before the finish.
  5. Damon

    Damon Veteran Member

    Nov 16, 2000
    Philly area
    The 502 is externally the same dimensions as the smaller motors- it's not a tall-deck or anything that would require custom parts to get the exhaust to fit. I say go for the cubes if you're laying down the kinda bucks they are asking for any of those motors. If you're going 454 or smaller I say just buy a used engine and rebuild it to your specs- the old Mark IV motors are still plentiful and cheap in rebuildable condition.
  6. 450bench

    450bench Veteran Member

    Feb 25, 2002
    memphis, tn-shelby
    I have a 454 HO and love it...Doesn't burn a bunch of oil at all...Massive torque and great power...Has boss for manual fuel pump...For the money, I like it better than the zz engines
  7. old zeder

    old zeder Veteran Member

    Feb 21, 2007
    Guelph Ont. Canada
    Buy the best with cash you have, the zz502 will give you the torque you need and then some
  8. DesmoEd

    DesmoEd Veteran Member

    Sep 9, 2009
    Frisco, TX
    427 would be cool - I'd love to build one.

    Its ok to give up some cubes, just give it plenty of compression and spin it up:bowtie:
  9. mjoc

    mjoc Veteran Member

    Apr 29, 2003
    Sherman Oaks, Ca
    Why not buy a motor from an aftermarket builder with better materials inside and more powerful power numbers

  10. Peter Wilson

    Peter Wilson Veteran Member

    The Big draw to me on the GMPP crate engines is they can be ordered at the local GM dealership , No freight ,and they can have it in a couple days . also how many performance motors have a 2 year warranty . where-as I live in Canada , if I buy from one of the name brand builders in the US , I have to pay shipping duty and taxes to get it here , if there is an issue or warranty concern , it goes downhill from there , dealing across border can be a pain , too many gov. agencies with their hands out trying their best to get ya for everything they can $$$$$$$

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