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Need some opinions on Matching up some engine compnents...

Discussion in 'The Garage' started by Silver84k5, May 4, 2004.

  1. Silver84k5

    Silver84k5 1/2 ton status

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  2. Bruiser

    Bruiser 1/2 ton status

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    I would ask them which combustion chamber size is 9.5 comp. since if it's with the 64cc heads they also have on eBay then with the heads you show at summit would lower compression. Also you do know that is a singe head for that price. I would buy some good vortec heads for that cam unless you plan to install a higher lift cam. You can get a good set of vortec's for half the price. Just IMO, hehe /forums/images/graemlins/waytogo.gif
     
  3. sled_dog

    sled_dog 1 ton status

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    whats this motor for? That cam is bigger than I would run in my crawler/trail rig. Cam and heads would match well for a mild mud motor.
     
  4. 84_Chevy_K10

    84_Chevy_K10 Banned

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    In a 383 that cam would be very mild.

    I'd run it, looks pretty decent to me.

    I wouldn't buy a short block from Ebay though.
     
  5. sled_dog

    sled_dog 1 ton status

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    could make more torque and bottom end with a smaller cam, but that will make good power throughout.
     
  6. 84_Chevy_K10

    84_Chevy_K10 Banned

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    Yes, but keep in mind, more CID will make a cam seem smaller.

    You're correct in that more low end can be had, but if you buy into that idea too much you'll end up with a tractor motor in your truck that dies at 3,000 RPM. That's fine for most folks but I'd hate it.

    That said this looks to me to be a pretty decent build, I think you'll be very happy with it. With twice as much power as you had from the factory, you're going to love it.
     
  7. Silver84k5

    Silver84k5 1/2 ton status

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    well i was pondering putting in a bigger cam.... This truck will be on trails, and in the sand..... The thing about this shortblock is... It is in my same city... So im not buying it blind ;P
     
  8. Silver84k5

    Silver84k5 1/2 ton status

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    yea after i posted this i looked farther down the Ebay page...

    I knew that was the price for one head on summit... but i didnt know that would lower the comp ratio... Thx...

    maybe i should just go with the heads they have on their other auction....
     
  9. 84_Chevy_K10

    84_Chevy_K10 Banned

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    I think AFRs come in 64 cc. /forums/images/graemlins/deal.gif
     
  10. 1-ton

    1-ton 1/2 ton status Premium Member

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    The heads and block should work together, but Summit says the heads are angle plug 72cc heads. Correct me if I am wrong, but I think this means they are an older style head (early 70's I believe), and you will need an older style intake manifold. Sometimes angle plug heads can be difficult to install headers on. 72cc combustion chamber heads are good for the street on pump gas though.

    The short block description says 9.5:1 flat-top pistons, but I think this company is fibbing a bit. Most flat-top pistons are 9:1 with 72cc heads, but rise to 9.5:1 only with 64cc heads, and not the 72cc you are buying. It is hard to tell whether the cam specs given are at .50 thousands inches of lift, or are what is called "advertised" specs. If this is full "advertised" specs, then this is a small cam. If it is cam specs given at .50 thousands inches of lift, then it should be fine.

    I have been out of building cars and trucks for so long that I had to look up what an Air Gap Intake Manifold was, and It is about time somebody made an intake manifold like this for Chevrolets. Chrysler and Pontiac V8 engines had been using this type of intake manifold for years, but not Chevrolet.

    This combination of parts should kick a$$...
     
  11. sled_dog

    sled_dog 1 ton status

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    there is nothing old style about those heads. They just have angle plugs for those who wish to run angle plugs. There is no, older style versus newer style intake, unless you mean TBI/Vortec intakes.
     
  12. Silver84k5

    Silver84k5 1/2 ton status

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    to tell you the truth... i saw 74cc and 64cc.... and just automatically thought bigger is better haha.... im fresh off the boat as far as engine building goes so im just tryin to learn what will work with what...... after reading your post and going with my First gut feeling i think i will go with 64cc. straight plug heads... i though that maybe the angle plug was for easier use with headers.... Thx for the input.
     
  13. 1-ton

    1-ton 1/2 ton status Premium Member

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    Correct if me if I am wrong, but this is the way I remember factory Chevrolet heads:

    1. Older style 64cc angle plug heads for carbureted (mechanical fuel injection for Stingrays) engines in the 60's,

    2. 72cc angle plug heads for carbureted engines in the early 70,s.

    3. 72cc straight plug heads for carbureted engines from the late 70's, to mid 80's.

    4. Center bolt 72cc straight plug heads for fuel injected heads for late 80's to mid 90's

    5. Vortec Heads, which I am not totally familiar with.

    Are the Summit heads in question new cores built by Summit, or are they rebuilt factory Chevrolet heads?

    I might be wrong about this too, but I thought there was a difference, in the manifolds, between an older head for carbureted engines, and a Center Bolt head for fuel injected engines.
     
  14. Bruiser

    Bruiser 1/2 ton status

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    Unless someone wants to refer to older style versus new style with the angle of the intake manifold center bolts changed angles.In '87 went from previous 90 deg to 72 deg. But most just elongate the intake to work anyways. I think they did the angle plugs for certain vehicles clearance. Nothing in my parts interchange manual saying these won't work on any block, but have heard that they are sometimes harder to use on headers. I still would put some votecs on it especially for a trail rig.
     
  15. Bruiser

    Bruiser 1/2 ton status

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    There is not set time that there was angle plug and can not be refered to as older, since 88 and up Corvette aluminum heads are angle plug. And also 3991492 '70-up could be had in either straight or angle version, it's a clearance thing. They did change the size of the plug in '71 though.
     
  16. Z3PR

    Z3PR Banned

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    If you have or will get headers, keep in mind some heraders won't work with angle plug heads. I usely go with 64cc heads because most you'll get a higher compression. I do like World Product Sportsman 2 heads. I've used them on more then one engine in the past and have always been happy. It's no secrete that I'm no fan of Edelbrock products. Everybody and there brother has Edelbrock, and I firmly belive that thier quality isn't what it used to be. Personally I'd get this intake manifold . For a block, check out http://www.rebuilt-auto-engines.com/cgi-bin/webc.cgi/home.html?sid=1AlF2z0-ICQC3DQ-13104297925.38 I really like thier 7 year / 70,000 mile warrenty.
     
  17. sled_dog

    sled_dog 1 ton status

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    [ QUOTE ]

    Are the Summit heads in question new cores built by Summit, or are they rebuilt factory Chevrolet heads?

    I might be wrong about this too, but I thought there was a difference, in the manifolds, between an older head for carbureted engines, and a Center Bolt head for fuel injected engines.

    [/ QUOTE ] You are right. TBI manifolds have different bolt angles. Vortecs are different from TBI heads. But all carburated heads I know of(factory anyway) are the same. By the way, those heads he listed are Aftermarket World Products Sportsman IIs.
     
  18. motofool

    motofool 1/2 ton status

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    i would go with pro topine heads or AFR or something else havent been hearing good things about world products heads from my machinists.
     
  19. Beast388

    Beast388 1/2 ton status

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    That short block looks to be a fairly decent setup especially for that price.

    Let me point out a few things.....

    Angle plug heads are only advantageous if you are using pop-up pistons....and sometimes header clearance. Most times, they interfere with headers.

    I can't tell from the pictures if the pistons in that shortblock are 4 valve relief or 2. /forums/images/graemlins/thinking.gif In my 388, I am using 72cc heads, with a 0.041 gasket, 0.045 quench, and 12cc D shaped dish pistons, my compression ratio is 9.463:1. With a 4 valve relief flat-top, the negative cc's on most of those are around 7. I would bet that the 9.5:1 comp. ratio is with 76cc heads.(I hate when piston mfg's say for example 9.5:1 piston.....there are too many other factors to give them a rating.)

    I would suggest getting some info on the pistons, and then make a decision about what cc heads to get. Be careful, unless the combustion chamber is CNC'd, there can be differences in the advertised and actual combustion chamber volume. My "67cc" S/R Torquers actually measure out to 72cc's.....I guess they built in some room for decking. /forums/images/graemlins/dunno.gif

    The camshaft in that short block is on the big side. I think it would run well in a truck, but it is going to make peak torque in the mid-range rather than just off idle. If you are a mudder, then perfect. /forums/images/graemlins/waytogo.gif

    Like I said, that short block looks great for the price! /forums/images/graemlins/waytogo.gif
     

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