Swap 340 for magnum 360

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Tech857

Tech857

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I have a 73 dart sport 340. It has the original motor and is all stock. Runs good. I was thinking about swapping in a stock magnum truck 360 to play with. Will this be an ugrade over the 340 or about the same power wise?
 
Horsepower ratings are different in the 340s favor, but depending on the state of tune and what parts you use on the 5.9, it may likely feel stronger...will probably feel better off idle into the midrange.

...just a guess though.
 
360 will have more torque in stock form than the stock 360 and probably around the same HP since its a 73 340
Should feel a great difference in power but mostly lowend grunt with a 360
 
I would not swap, 340 has lots of potential for up grades and are very desired in 340 cars with 400 hp on tap with good bolt on parts
 
K.O. SWINGER said:
I would not swap, 340 has lots of potential for up grades and are very desired in 340 cars with 400 hp on tap with good bolt on parts
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Granted I don't know the OP, but I *think* he might have that in mind...use the 5.9 to have some fun and build the 340 for later...?

EDIT: Besides, a 5.9 has lots of potential too. They'll respond favorably to purposeful and well thought out mods just like any engine.
 
K.O. SWINGER said:
I would not swap, 340 has lots of potential for up grades and are very desired in 340 cars with 400 hp on tap with good bolt on parts
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This is the exact reason he should swap, 340's are rare and expensive. Magnums are cheap reliable and run foooooorrrrevverrrr. 200k miles and no bore wear? Sign me up. Go for it, but get the cam reground to something to your liking. Heads are known to crack and leak water between the valves. You could get a set of engine quest heads on the cheap if this is so.
 
txstang84 said:
Granted I don't know the OP, but I *think* he might have that in mind...use the 5.9 to have some fun and build the 340 for later...?

EDIT: Besides, a 5.9 has lots of potential too. They'll respond favorably to purposeful and well thought out mods just like any engine.
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You got it. The 340 has 40k on it and is the original motor. The car sat out side for 30 something years. It was stuck when it got the car and freed it up gently and slowly with some mystry oil. It seems to be fine good oil pressure runs cool ect. But i would like to set it aside go through it and not risk blowing it up having fun. I can get a 360 cheap. What will work and what problems will I run in to?
 
There is nothing too special about a bone stock 73-340. About 8.5:1 compression 1.88 intake/1.60 exhaust valves. Crank is not forged either and it's external balance.
Do people desire them?. Yes for whatever reason. I have one I just pulled out if my scamp that I am going to do a pretty good build on here in the next couple months.

If I were to start a build from scratch it would be 360 based & LA not magnum everytime. The LA valve train is way superior than the magnum that has the stud mount rockers. Roller Lifters are now a drop in deal for the LA so for me LA wins no contest.
 
I would make sure to have the magnum heads checked out. They are prone to cracking. Otherwise they are good motors. Roller cam. The heads flow well, and the R/T heads even better. If stud mount rockers bother you, you can get shaft conversions.
 
Tech857 said:
Can you put LA heads on a mag block?
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yes..all you have to do is get oil to the rocker shafts......and if the magnum block is not drilled nor has the correct cam bearing or if the cam is not drilled for the to supply oil to the heads....





see it is pretty easy...LOL

that 73 340 probably does not make anymore hp the the magnum truck engine...and the 360 has more potential for hp then the 340...bigger is better....do the same mod to 360 as 340...360 will win..
 
So what would you build for a 360? Cam heads ect. I can get a discount on any parts from Mopar performance. Maybe I should look for a roller LA 360 and Put mopar performance Al heads on it?
 
I would get a used 5.9 Magnum shortblock or roller cam LA 360 and go from there. How much can you spend? lol If you can afford it I would say Edelbrock heads and an upgraded roller cam with a mech. fuel pump snout. If not then EQ or RHS iron heads but either way try to keep the roller cam.
 
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