Help with sb combo

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Did you run this engine previously? How'd it do? Were the heads ever flow tested? Who ported them?
 
My dad had this motor in a dart he bought 20 yrs ago and yes he ran it. Motor was suppose to have went 7.40-50s. I believe the heads are just home ported no big expensive job.
 
I think your asking a lot from 93 octane with 12:1 squeeze.

For an intake, and these are personal preferences, are a LD340 style dual or a Strip Dominator for a single.

I swear by, again personal likes, Comp Cams when working in the .500 to .570 ranges. I'd crunch the numbers on the Comp that SST Mike has.
 
supersean said:
well im planning on running a thicker gasket to bring it down to 11 ish
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There is no way it will run on 93 octane with old style iron heads and that compression unless you pull a metric TON of timing out imo
 
supersean said:
m putting a mild 340 back together to hopefully run this coming season. Im torn between what intake and cam I should use. Car will be raced not street driven, only the occasional car show.

340 - .30 around 12 ish comp
TRW pistons
Worked stock 340 rods
318 crank
J-heads milled with a lil work and large valves
904 w/9 in conv stalls around 4500+ on fb
750 Holley

Before anyone says anything about getting new pistons/rods, that isnt an option. Im using what I have unless something ends up being broke. that being said what intake and cam do you all recommend? A few options Im considering

296/ .557 cam
296-298 . 577 int .555 ex cam
or suggestions??

Mopar single plane or Air Gap??
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Here is my question.

318 crank with stock 340 rods and piston?
are they dome or flat top pistons?
2 valve or 4 valve piston top.

IF you have a "light" crank(318 ) there is, or will be, a lot of mallory ($$$)metal in it. If you ballance/d it.
Before anyone says anything about getting new pistons/rods, that isnt an option.
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I think, you might want to consider it......................
 
this is a gr8 conversation u got here now my only issue would be to open my j heads a little or go to a set of aluiminums like the rpms or the new 1ns pro comp is putting out they are 2.02/ 1.6 roller rocker 65 cc with 190 runner with a port matched air gap intake put that on my 360+ 30 or stroke it to a 408 and ive got a 3200 stall 727
in front of a 3' 91 and play with tire hidth 28 inch all in a 65 barracuda
 
I think, before you spend too much on anything, you need to find out what you have there. 7.40s is no real slouch and if the heads can move some air you might as well take advantage of it. Same deal with the pistons - If you can calculate the compression based on actual chamber measurements, and actual piston/bore measurement (1" down method) then you know what you have, and we can help a little more. So I'd have the heads really checked out - see what they have for flow, spring capabilities, and chamber size. While a head's off being tested measure the volume of the piston/bore combo, then go from there.
 
Is it just me, or isn't the 318 stroke different from the 340? Sure it will fit, but may change final comp. ratio.
 
chad67gtdart said:
Is it just me, or isn't the 318 stroke different from the 340? Sure it will fit, but may change final comp. ratio.
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Same.......273,318,340 = 3.31 stroke
..........................360 = 3.58 stroke

Cube difference is in the bore..
318 = 3.91
340 = 4.04
 
I would spend money on rods and pistons before I sprung for a custom grind cam. Even lightening the existing pistons if they checked out well enough. I do have a brand new set of ARP waveloc rod bolts if you need them though.
 
OldmanRick said:
Same.......273,318,340 = 3.31 stroke
..........................360 = 3.58 stroke

Cube difference is in the bore..
318 = 3.91
340 = 4.04
Click to expand...

I believe the industrial LA 318's
Where forged cranks
 
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