What to do with it?

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1967DartGT

1967DartGT

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Several years ago (before 4" stroker cranks were really available) I picked up a new 3.58" crank with 318/340 mains. I have not used it yet and 4" cranks are now everywhere. Just curious to see what others would do with it. Right now my options are:
1) Use it in my 318 to make a ~349.
2) Use it in my 273 to make a ~300 and just to be different.
3) Sell it (probably for a loss).
 
If its a steel crank, which I believe they are, find a 340 block and some w-2 heads and build a nice 372. No question.
 
MP also made cast cranks 3.58 stroke and 340 mains...I know..picked up one at a good price a few years ago...
 
Yah, it's a dilemma. If I had a 340 block it would be a no brainer, but unfortunately I don't, and I don't anticipate one in the foreseeable future. However I do have two 318s and the 273 available.

Originally I got the crank for the 273 in order to keep the stock block with the car. I figured it might make a screaming little 300 c.i. class engine by shaving down the pistons and using a set of 302 heads I have. Would have been an honest 9-9.5:1 c.r., and using flow numbers from BJR Racing, CamQuest estimated around 400 h.p. with a XE268H cam.

But then I picked up the 318s cheap and figured I could get the same h.p. with about 50 ftlbs more torque from them, non-stroked.

So then I considerd the 349, but that will depend on the cost of pistons and ballancing to determine if a junkyard 360 would just be cheaper in the long run.

If I go with a 360 though, I think I'll need a new transmission. Mine is a 904 and I'm not sure if it can be externally ballanced.

This is the problem with trying to make a combo from available parts rather than coming up with a real plan before shelling out dough for crap I really didn't need. Or the problem with not being able to make up my mind and accumulating so much crap that I lose focus.

Thanks for your thoughts on this ... eventually I'll get my mind made up.
 
Decisions - decisions ! Don't fret over it !

Look at the post from 340sfastback. That's the way to go. You can use stock low CR cast pistons and do it cheap if you want.

For what its worth - Ive been finding that most of the later 318's that had moly rings in them when new, have almost ZERO wear in the bores. A motor my son and I picked up for free (an 87 or 88 318 roller block) had no more than .001 to .0015 wear in all the bores, checked at three points on the thrust and non thrust surfaces. That's darn good, it means you can use stock standard size pistons. We also built another late 318 that had similar wear = zero.

I'd pick your best block after measuring it out, hopefully you'll have luck like us. Hot tank the block, new cam bearings, freeze plugs, a quick hone job, and balance the mess together.

Run some # 302 heads on it after bowl porting and 1.60 1.88 valves, or put some 360 heads on and run it.

My .02 !

Have Fun deciding !
 
Use it in a .060 over 318 with the 302 heads and the rest.JMO
That or what buy $350 inserts to run it in a 360? f that, may as well buy a stroker crank if you wanna spend money.
 
3404spdvaliant said:
Use it in a .060 over 318 with the 302 heads and the rest.JMO
That or what buy $350 inserts to run it in a 360? f that, may as well buy a stroker crank if you wanna spend money.
Click to expand...

I wouldnt waste much time with a .060 over 318 block. Probably pretty thin and you could easily find a standard bore block for real cheap.

also 3.58 is standard 360 stroke so buy the spacers would be a waste. You can buy a new 360 main 4" stroke crank for less.

I all ways wanted to do a 372 using a 340 block for some reason.. But its really the same thing as a .100 over 360. If you can find a block that would go that far.
 
That meant bore .060 over for cubes and no they don't run hot at .060 over like your 350 does.lol
BTW 360 .060 over is 370 =D>](*,) 2 cubes?
come on?
 
3404spdvaliant said:
That meant bore .060 over for cubes and no they don't run hot at .060 over like your 350 does.lol
BTW 360 .060 over is 370 =D>](*,) 2 cubes?
come on?
Click to expand...

You can run all the .060 over blocks you want. I'll stick to the thicker blocks. Differences in opinions is what makes the world go round.
 
I,m running a 372c.i It,s 452 hp at 5700rpm 438ftlbs at 4400rpm.I,m pretty happy with this motor,could have gone 408c.i 550hp.Wasn,t in the budget at the time of build.
 
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