Help me decide.....306 or 331.

Discussion in '94-95 5.0 - Specific' started by 96juicedgt, Jun 2, 2007.

  1. 96juicedgt

    96juicedgt New Member

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    I am trying to make up my mind so I can get this thing to a machine shop. I am torn between a 331 and 306. I will be using the stock block :slap: It will be topped off with either a KB matched to a cobra lower, or a Trick flow intake. I already have both so I wanna stay with one or the other, I really like the idea of a KB since there are no KB cars in my area. I already have a F303 cam that I bought and haven't used so I would like to use it if at all possible. Thinking about some TW heads. Any info or combinations you can suggest are welcome!!!!
     
  2. Magic

    Magic Well-Known Member

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    if its a stock block...they are good for upto 500 rwhp....I know there are some out there making more jam, but theyre hanging on by a thread.
    Do you still have the stock crank and rods? If so, upgrade to ARP rod bolts and find some 87-92 forged pistons, and then get them flycut (larger valve reliefs)....
     
  3. Suspect

    Suspect Well-Known Member

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    also ull prolly have to sell the trickflow intake. cuz i dont think it works with the kb. check their website to be sure tho.
     
  4. 96juicedgt

    96juicedgt New Member

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    I know the trickflow intake wont work with the KB, I was just saying that I will be supercharging the car. If I keep the trickflow then I will probably go vortech or paxton. Just wanting to decide on what needs to be done to help hold this thing together with the stock block.
     
  5. p-351

    p-351 New Member

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    As the old saying goes----"There is no replacement for displacement!" I vote for 331 :banana:
     
  6. sykostanger

    sykostanger New Member

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    331
     
  7. Magic

    Magic Well-Known Member

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    this is what I would do....
    302/306 (with stock crank, stock rods with ARP bolts, and 87-92 replacement forged pistons (or .030 over)), Edelbrock Performer (60379) or TFS TW heads, Edelbrock RPM II intake or TFS Track Heat, something like a B-cam (yes it will work fine, or go for something a little more radical like a Comp Cams grind or a custom grind)....Vortech S-trim pullied for 12-psi along with a good fuel system (minimum 255 HP intank fuel pump, larger feed line, rails, external aeromotive boost sensitive regulator, 42lb injectors)....with a good dyno tune, you should be thumping down at least 450-475 RWHP.....more than enough for the street.......

    If you want more HP, build up a 331/332 in a new BOSS302 or Dart block....cuz like I said before, stock 302 block is only good for 500-530rwhp....
    if you cant afford the price of an aftermarket 302 block, then step up to a 351W.....stock 351W block is good for roughly 650-700 RWHP....
     
  8. 96juicedgt

    96juicedgt New Member

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    thanks for the reply's...i was thinking about getting a new boss block from latemodelrestoration as they are the cheapest I have seen on the block. what would be a good rotating assembly to mate with that? I was thinking either eagle or scat. any suggetstions on the rotating assembly components?
     
  9. Paul

    Paul Legend

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    If you're going to spend all the money on a Boss Block, then make sure to get good 4340 forged internals, H-beams (or billet I-beams if you've got cash) and some nice pistons.

    I've had bad luck with both Scat and Eagle, but most people have great luck. I'm just cursed. :)

    Paul.
     
  10. Magic

    Magic Well-Known Member

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    what was this bad luck, if u dont mind to tell your tale....
     
  11. Magic

    Magic Well-Known Member

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    Eagle makes some good stuff....I would go with the 331/332 stroker kit with their forged crank rods and pistons....
    Where are u located (maybe help point you in the right direction for a machine shop or engine builder)?
     
  12. Paul

    Paul Legend

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    Well, my old 418 had a set of 6.200" 4340 Forged H-beam Eagle rods in it. The engine had low oil pressure so I pulled it apart to inspect it. After only 7000 street miles, maybe a half dozen passes down the track, and a few dyno pulls - my rods had cracks in them already. The machine shop noticed it when I took them in to have them honed. That was not a cheap set of rods either. This couldn't be due to power production either because even on spray the most the motor made was 487 rwhp and 615 rwtq. That shouldn't be enough to crack a set of forged H-beams. So, no more Eagle for me. I replaced them with a set of Oliver billet rods that set me back a whopping $1100 - but at least I know these won't crack.


    As for SCAT. When I reinstalled the motor, I got a new SCAT 4340 Forged Nitrided 4.100" stroker crank. Again, this was NOT a cheap crank. After getting everything back together and firing up the motor. I had a HORRIBLE oil leak. It was coming out of the bellhousing so I figured I blew out the rear main seal somehow. Took everything apart and this is what I found... I would never believe it myself unless I had a picture to prove it.

    [​IMG]

    SCAT actually drilled the pilot bearing hole so deep that it breached the oil journals, and oil was spraying directly out of the center of my crankshaft. You can imagine how pissed I was after having spent so many hours getting everything back together only to find out that EVERYTHING MUST BE DISASSEMBLED AGAIN, INCLUDING THE MOTOR.

    Fuck SCAT and Eagle. I'll never buy their shit again. I'm probably going to get my next crank from Lunati or Oliver, and I'll be purchasing Oliver rods from now on.

    Paul.
     
  13. Magic

    Magic Well-Known Member

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    I know the Windsors have oiling issues sometimes (remedied with installing oil restrictors).... would this cracked rod possibly be due to that? or just a manufacturing flaw?
     
  14. Paul

    Paul Legend

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    I could see low oil causing scoring in the bearing, but not cracking the rods. I think it was manufactured wrong.
     
  15. jbeez

    jbeez New Member

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    So do you really want to use a stock block or aftermarket? What kind of money were you thinking about spending.... thats usually the deciding factory on what you can do. Most people say take your estimate and triple it and thats usually what it ends up costing lol

    Will you be doing the work or having a shop do it?

    If you're not doing the work, I suggest you talk to a few reputable shops around and find one thats recommended by some other stang guys, see what they think for your combo, what they can get everything done for, sometimes they can get some better pricing, plus theres a ton of little BS that you miss when you try to do an engine swap that you might not be thinking about off the top of your head, but these guys might do this sort of thing regularly, so they just know what commonly is needed, etc.
     
  16. slow96mystic

    slow96mystic New Member

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    a stroker motor with a power adder is usually a waste of money if you're using a stock block. a well built 306 with nitrous or a supercharger can easily make more power than the stock block can handle, so why spend the extra money?
     
  17. 96juicedgt

    96juicedgt New Member

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    If I could get buy with doing a nice 306 than I would much rather do that. I already have a place to do the machine work in Ashland KY. I may let them assemble it also, or me and my dad may do it, we install everything on my cars (he was a mechanic for 23 years)

    Just wondering what would be a good combination to use as far as internals, heads, etc.
     
  18. Magic

    Magic Well-Known Member

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    if you are going to be adding boost to it, try and keep the cylinders standard bore (302)...go .030 over if you absolutely have to(306) ie. scorred cylinder walls etc......

    as said before, stock 302 block is only good for around 500-550 rwhp.....so for a good rotating assembly....stock 302 crank, either stock 302 rods with ARP bolts or a set of aftermarket replacement/better than stock replacement I-beam rods...and some forged pistons (JE, Speed-Pro, etc)....

    as for a set of heads, Edelbrock Performers do a very good job (even with 1.90/1.60 valves, you dont need to go with a 2.02 valve)
    Intake....if youre going with a centrifugal blower like a Vortech, then something like Trick Flow Track Heat or Edelbrock Performer RPM II intake....
    Cam..any blower spec oriented cam should do...