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1995 Silverado 1500 5.7L TBI 4*4

Discussion in 'Chevy Trucks' started by hurley2323, Jul 9, 2003.

  1. hurley2323

    hurley2323 Junior Member
    Messages: 2

    I am getting ready to replace my 5.7L in my truck and was wondering if this year of truck came with a 2bolt or 4bolt main? I need this when i order my engine.
    Dan
    PS This truck is a 5.7L TBI :help:
     
  2. ratlover

    ratlover PlowSite.com Addict
    from IL
    Messages: 1,325

    All the stuff interchanges between a 2 bolt and a 4 bolt block. well except the caps, block, and the different number of main bolts that is........it dosnt really matter. A 4 bolt has a bit more beef but if you arent doing any racing or wild stuff a 2 bolt will be fine.



    Are you just ordering a GM shortblock or geting a rebuild from a rebuilder or a new GM crate?

    I believe you have a 2 bolt. BTW
     
  3. John DiMartino

    John DiMartino PlowSite.com Veteran
    Messages: 2,154

    You have a 2 bolt block, the 4 boltss started over 8500 GVWR. Id stick with a 2 bolt replacement,especially if you getting a long block,they make more power than the 4 bolts engines.
     
  4. wyldman

    wyldman Member
    Messages: 3,265

    Itmay be a 4 bolt !

    It just may have a 4 bolt in it.I have seen a few,all were extended cab 4X4's,with 4 bolts.They were all 1500's.Most were original engines.

    Maybe the 4 bolt was used in the 4X4 ext cab and up trucks ?
     
  5. ratlover

    ratlover PlowSite.com Addict
    from IL
    Messages: 1,325

    :confused: What do you mean 2 bolts make more power than 4's? :confused:

    Not trying to start anything I just must be misunderstanding you or something......
     
  6. wyldman

    wyldman Member
    Messages: 3,265

    I know sometimes the trucks with HD emissions make less HP.But this is usually due to different emission items,and sometimes programming,like fuel and spark curves.

    Don't think it makes a difference for 2 or 4 bolt.Is there something your not telling us John ?
     
  7. JohnnyU

    JohnnyU 2000 Club Member
    Messages: 2,040

    In those years, if I'm not mistaken, the trucks over 8600# gvwr had a different cam, thus producing less hp, but higher torque. Is that correct?
     
  8. wyldman

    wyldman Member
    Messages: 3,265

    I don't know off hand what OEM cams were used,but I do know that the rebuilders all use the same cam for 2 bolt,4 bolt or whatever.Doesn't seem to make a difference power wise,and no effect on emissions based on the emission testing we do.

    I'd take a 4 bolt if you can get it,and not have to pay any extra core charges.
     
  9. John DiMartino

    John DiMartino PlowSite.com Veteran
    Messages: 2,154

    The 2 bolts make more power because the MD heads the 4 boltsa use do not breathe as well as the LD heads on 2 bolts.4 bolt engines are built to basically run WOT for long periods,so they have HD valves and seats,these are more restrictive . The newer vortec engines starting in 96 may be different.
     
  10. wyldman

    wyldman Member
    Messages: 3,265

    Your right John,I spoke to my engine guy,the HD heads are different.HD seats,and bigger valve stems (3/8" vs 11/32").There is not a huge difference in flow,and should not make a difference for a truck engine which rarely goes over 3500-4000 RPM.

    The cams are also different,the HD cam will make more bottom end torque,but less top end HP.

    So if you want low end power and torque (which is what a truck needs),go 4 bolt.If you want top end HP,go with a 2 bolt.

    I'd also ask the rebuilder to make sure he is using the right stuff.
     
  11. wyldman

    wyldman Member
    Messages: 3,265

    Edit - double post
     
    Last edited: Jul 11, 2003