Want to build a 318

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67Notchback408

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Ok so this isn't for my a-body. It's for my ramcharger plow truck. I need suggestions for pistons and a cam. I have a set of 302 heads and an ld4b intake. I am building this to plow with. So lower rpm torque will be the focus.
Thanks in advance.
 
Then you don't need to change the cam or intake. You won't be opening up the 4 bbl.'s when plowing. Putting a fresh set of 302's will help. Advancing the cam 4 degrees moves the power band down a little, and is cheap. I suggest playing with the gears. Add some gearing to take some stress off of the tranny, and the gearing will make it feel like more low end torque. If you really want more low end grunt, might want to consider a 360, they are cheap and available.
 
I'd go with any stock cast piston, and keep it down in the hole a bit for a modest CR; you have around 8:1 true CR with those heads and could bump it up a bit with the .039 or .028 head gaskets. I'd stay around 8.0-8.5:1 SCR. And then use any of the high torque hydraulic cams like the Crane H-248-2. (Or one of the smallest Lunati High Efficiency cams if you prefer that brand.) Carb: 600 cfm or even a 500 cfm 2 bbl. Not sure how good the ld4b is for low end use...but I have a used a super low duration, high lift cam with a single plane and the engine produced very good towing torque.
 
I'll asssume that since your asking about pistons, your going to need them in an engine that needs a rebuild. The earlier engines, like the '69 - 318 had a higher , or I should say a taller piston for an advertised higher ratio of 9.0-1 back in the day.

As far as a cam goes, the above Crane cam, a low duration and lift cam on a 112 is what I would look for. Your operating in a low RPM band and high lift isn't needed. The heads should be prepped at the valve seat to take advantage as much as possible for the low valve lift flow. It's all in the valve job at this point.

The LD4B is a fine intake for this. No more than a 600 cfm carb.

Here is a similar Comp Cam;
http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=617&sb=2
or
http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=624&sb=2
 
Thanks fish the the comp cam you mentioned is the one I had my eye on. Thank you for the reassurance. About the heads. I had planned to have a valve job done. Would I benifit from light porting and stepping up in valve size or will I loose to much velocity? Also headers or manifolds for this application. If headers I assume small tube? Thanks again
 
some mild porting will help rather than hurt you. the transition below the seats, any sharp edges, general smoothing/deburring. #1 get the right cam & possibly adv it 4 deg
 
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