best cam for the $1550 GM crate 350?

Discussion in 'Engine Topic' started by 351maverick, Jun 3, 2012.

  1. 351maverick

    351maverick Veteran Member

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    erie, PA
    so I'm looking at this GM crate 350 for a replacement of the tired 305 in my 86 monte carlo

    http://www.summitracing.com/parts/NAL-10067353/

    $1550 & free shipping....I can't do better than that rebuilding anything that I've got, and this is NEW

    so I've heard that the only difference between that motor & this motor is the cam:

    http://www.summitracing.com/parts/NAL-12499529/

    ...but I like the higher 290hp rating

    so my thought is to buy the $1550 motor & replace just the cam - I should be able to use the original lifters because I don't think GM runs these engines before shipping them

    the car is my daily driver, currently the 305 is 165hp so this would be a great improvement, I'm just not sure of the best cam choice since these are just 8.5:1 w/76cc heads

    the car has the original (still nice & tight) 200R4, the original convertor which I would like to keep & 3.08 gears, and 225/60/15s on the rear....Edelbrock 600, regular HEI, headers & a pair of dumped Flowmasters

    the intakes I have are an Edelbrock Performer or a Torker II

    and NO I do not want to convert to an LS anything
     
  2. hhott71

    hhott71 Veteran Member Lifetime Gold Member

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    Change heads. 64cc chambers will get you 9.5: 1 and that's a big boost in itself.The old stand by .454" lift 216* cam (any MFG) is perfect to add a real boost.
    3.73 gears will also be a big kick in the butt. The 0.67 : 1 OD drops it to 2.499 rear ratio.
     
  3. Air_Adam

    Air_Adam Veteran Member

    Why not go for the 290hp? Its basically the same, but with the L82 cam. I bet that L82 cam would work nice with a set of Vortec heads....
     
  4. Damon

    Damon Veteran Member

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    For a motor that mild the XE256 is about as big as I'd go. And you're going to want to upgrade the valve springs when you do it. Even though it's not a big lumpy cam the lobes are much more aggressive than tht stock cam and will work the valvetrain quite a bit harder. I just qestion whether the upgrade is really going to be worth the time and expense of doing it. If you don't want to touch the valve springs then use an older lobe design like the base model Edlebrock Performer cam (also sold as the Summit house brand 1102 for silly-small bucks).

    Changing over to Vortec heads without touching the cam would probably net you the same or more power, but would cost even more (and it sounds like those funds would not be in the budget).

    Your call.

    Definitely use your Performer intake on that moto, not the Torker II.
     
  5. my24ktrat

    my24ktrat Veteran Member

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    ...Or try the regular Comp cams 268 with the performer intake , should run nice in a stock 350, just my.02, DC:bowtie:
     
  6. Todd80Z28

    Todd80Z28 Moderator Staff Member Lifetime Gold Member

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  7. 351maverick

    351maverick Veteran Member

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  8. Todd80Z28

    Todd80Z28 Moderator Staff Member Lifetime Gold Member

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    I can relate, but after the cam swap, you're looking at $300 difference. You will need to drop another $200 or so on the correct manifold.

    '86 305- is that one-piece or two-piece rear seal? I know the 350s went to one-piece that rear, so dropping back to a Goodwrench two-piece means new flex plate.

    Personally, I think the Vortec will net you much better performance for the roughly $500 difference. I think that 255hp rating was stock factory, whereas the 250hp rating on the Goodwrench was with headers, exhaust, etc... Put some 1.6 rockers on the Vortec and forget the cam.:)

    I know you'll disagree. I'll leave it from here.
     
  9. markw

    markw Veteran Member

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  10. Damon

    Damon Veteran Member

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    Remember that CarCraft was also going to as much power as they could get with cheap parts. Drivability wasn't high on their agenda. That cam would be too much against a stock stall converter and mild gearing. The last thing you want to do with a low compression/meidocre heads motor is stick too much cam in it.

    Leave the cam alone or choose something very mild is my advice.

    Just as a point of reference, the cam that comes in that Goodwrench motor has specs something like 192*/201* @ .050, .390"/.410" lift (w/ 1.5 rockers) and a LSA of 112*. That's from memory, so don't quote me down to the single digits.

    That means even the Summit 1102 cam is already 10*+ more duration and almost half a thenth more lift on both intake and exhaust than the Goodwrench cam. That's a noticable change when you consider how mild the cam is you're starting with.
     

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