1970 Jeep P/U w/ SBB 350 low end performance questions

Discussion in 'Small Block Tech' started by Resbum, Aug 25, 2010.

  1. exfarmer

    exfarmer Well-Known Member

    Cool truck & what a steal at 300 bucks! It's definately more fun being "different"!
     
  2. Resbum

    Resbum Member

    OK, this thread has ended up being more than I ever imagined it would. In an effort to condense all the great info and opinions shared so far Ive cut out all the fluff and posted it here. Ill start at the air cleaner and work my way the tail pipe.
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    Heres what I want to achieve and originally asked:
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  3. Resbum

    Resbum Member

    Air Filter and supply plumbing: Has not been addressed
    Ill run a good quality air filter and fabricate low resistance cold air plumbing

    Carburetion: <?xml:namespace prefix = o ns = "urn:schemas-microsoft-com[​IMG]<o:p></o:p>
    My original q-jet plans appear to be totally off the mark.
    Post #3 Sean Buick 76 points out the benefits of using the 2bbl
    Post #4 No Lift suggests Holley or Edelbrock 600 CFM, also agrees w/ Sean Buick about 2bbl and explain why. They also give good advice about the riser/adapter.
    Post #8 Sean Buick suggests the 800CFM q-jet and gives a good explanation for that.
    Post #9 Lightningbird talks about the OEM 2bbl with a good explanation. Suggests EFI with good explanation. Suggests the q-jet would be hard to get dialed in for this application

    Intake Manifold:<o:p></o:p>
    My plans; mild cleanup work and make sure its port matched
    Post #5 No Lift Port work and port matching is a waste of time unless you have head ports intruding into the intake ports causing reversion.
    Port #8 Sean Buick 2. If you do go with a square bore carb then consider the Alum TA intake since it is made for either spread or square bore carbs. The weight savings is also nice however remember that it has no provision for divorced choke...
    Post #9 Lightningbird stock intake along with the intake manifolds tall narrow long runners that maintained high port velocity at low RPM. A factory 4 barrel intake manifold would work best in any situation when concerned with low end torque.
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    Head Work:<o:p></o:p>
    My thoughts. Port match intake/exhaust for smooth air flow. Nothing crazy. Do some basic cleanup work in the runners/bowls. With a surgeons touch remove any probable hot spots from the chambers and cc chambers. I have an old piece of Plexiglas I used on another chamber project to cc them.
    Post #4 Sean Buick Have the heads ported by a pro and have them focus on the low and mid lift numbers.
    Post #5 No Lift Whatever headwork you can have done , have done but all out heads aren't necessary. Port work and port matching is a waste of time unless you have head ports intruding into the intake ports causing reversion. Your ports are plenty big. Worry about opening up the bowls under the valves.
     
  4. Resbum

    Resbum Member

    Camshaft:
    My thoughts are for the Lunati cam #67000
    Both Sean Buick and No Lift suggested the TA cam #RV212
    Post #9 Lightningbird The factory camshaft has in no way has the ability to be used in a racing application as all of the power is delivered below the factory 5200 RPM redline. Utilizing your factory camshaft as delivered would not hinder the 350's ability to ever pull anything, all torque is delivered at a meager 3200 RPM and that's Big Block 410 ft/lbs in some cases of the engine. with 8.5 - 9.5:1 compression. That would allow for the use of regular 87 octane fuel when using a stock or RV camshaft that focuses on maintaining cylinder pressure vice bleeding it off like a drag racing camshaft with ample overlap of valves. As you can see, I did not say an RV camshaft, because I feel it is not needed. The stock camshaft is almost the same, costs nothing and provides decent fuel economy.
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    Valves:<o:p></o:p>
    My thoughts are to put in larger TA valves
    Post #5 No Lift Bigger valves probably won't help either.
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    Roller Timing Chain and Gears:<o:p></o:p>
    My thoughts were for it and it was recommended in other posts
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    Distributor and Timing:<o:p></o:p>
    Possibly electric guts in the distributor and set up appropriate curves.
     
  5. Resbum

    Resbum Member

    Pistons and Compression:
    My original thoughts were 9.5:1 cast pistons
    Like carburetion there was a lot of good opinions shared, so Ill summarize:
    Originally Sean Buick recommended 10.5:1 forged pistons, but seems to have graciously bowed to the arguments of No Lift, Lightningbird, for 8.5:1 to 9.5:1 forged piston for towing applications.
    Read Posts #5, #9- Lower compression for unique towing demands, less detonation, long hot pulls, more ability to play with timing. Forged pistons for durability and newer technology lower friction rings.
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    Exhaust:
    My thoughts are towards port matching and a fabricated Try-Y header made of 1 5/8 stainless to handle the heat, coated, and a 3/8 inch thick flange. Tri-Ys have been proven to my satisfaction for their low/mid range gains.
    Post #5 No Lift suggested a TA header.
    Post #9 Lightningbird makes very good arguments for using a factory manifold.
     
  6. 26Troadster

    26Troadster Well-Known Member

    don't get me wrong i like my buford motors but the amc v8's in the jeep trucks are my flavor, and that is coming from someone that has a 350 bsb in a 63 cheby truck, when i moved to alabama about 25 years ago i had a 77 cheby truck with a 343 amc in it.
     

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