POLL: 360 magnum or 3.58 stroke 340?

What engine would you build?

  • 360 Magnum

    Votes: 58 49.2%

  • 3.58 Stroked 340

    Votes: 60 50.8%
  • Total voters
    118
  • Poll closed .
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do u have the 340 crank, is it 1968-71.5 forged steel? 360 is only cast, and has larger mains that can be ground down by a good crank grinder. then balancing the 360 crank assembly can be more work. and they say many magnum heads are cracked, and what else is different when swapping from an la to magnum?
 
Marcohotrod said:
do u have the 340 crank, is it 1968-71.5 forged steel? 360 is only cast, and has larger mains that can be ground down by a good crank grinder. then balancing the 360 crank assembly can be more work. and they say many magnum heads are cracked, and what else is different when swapping from an la to magnum?
Click to expand...

Take some time and read this

http://www.magnumswap.com/
 
Thanks for all the comments! The 340 I have is a cast crank motor, and will need a good deal of machine work, thats why I thought of using a 3.58 crank in it (especially since I have a LA 360 rotating assembly on the shelf) The Magnum 5.9 deal Just came up and I do know that its a good running engine. The guy drove it everyday to work.
I read that it is really easy to make good HP out of the magnums and with a little work and a good cam/heads etc... you can get a Dart in the low 12's rather easily. I have 3.91's, a really good trans w/2500 converter and a 3000 converter on the shelf. I'm thinking that it may just be cheaper to build the magnum with a roller cam than having the 340 built, and probabally make more power, easier.
 
gliderider06 said:
Thanks for all the comments! The 340 I have is a cast crank motor, and will need a good deal of machine work, thats why I thought of using a 3.58 crank in it (especially since I have a LA 360 rotating assembly on the shelf) The Magnum 5.9 deal Just came up and I do know that its a good running engine. The guy drove it everyday to work.
I read that it is really easy to make good HP out of the magnums and with a little work and a good cam/heads etc... you can get a Dart in the low 12's rather easily. I have 3.91's, a really good trans w/2500 converter and a 3000 converter on the shelf. I'm thinking that it may just be cheaper to build the magnum with a roller cam than having the 340 built, and probabally make more power, easier.
Click to expand...

You are 100% correct
 
gliderider06 said:
Thanks for all the comments! The 340 I have is a cast crank motor, and will need a good deal of machine work, thats why I thought of using a 3.58 crank in it (especially since I have a LA 360 rotating assembly on the shelf) The Magnum 5.9 deal Just came up and I do know that its a good running engine. The guy drove it everyday to work.
I read that it is really easy to make good HP out of the magnums and with a little work and a good cam/heads etc... you can get a Dart in the low 12's rather easily. I have 3.91's, a really good trans w/2500 converter and a 3000 converter on the shelf. I'm thinking that it may just be cheaper to build the magnum with a roller cam than having the 340 built, and probabally make more power, easier.
Click to expand...

Hell,you're almost done. The converter/gears/ car,is already set up for a warmed over Magnum. It's what was offered to me,glad I took the choice.
 
And to the (as of now) 17 people who think stroking the 340 with a 360 crank is a better idea, why note post the reason WHY you think its a better idea? should be interesting.
 
More intake selections
More piston selections
More head selections
More rocker selections
More valve selections
More cam selections
Smaller mains = less drag, more power
(OK, I even think that's crazy but it is true though you would never feel it.)

The following can be done one way and not the other.

Head swap between LA and Magnum not a problem.
LA can use a Magnum head, Magnum can't use an LA head.
Stronger valve train set up.
LA to Magnum cam swap easier. Magnum to LA cam swap not possible OR you'll need a. Entire LA front.

I myself like the bigger bore though someone said very accurately you'll never feel or know a .040 larger engine. That's OK, the dyno will show you and the drag strip will show everyone else with all other things being equal.

But this is what I would do with it all. I may sound like a hypocrite, so here it goes, while I did t have the choice the OP has, I just recently raised a '00 Magnum 5.9 for my B body build and swapped on bolt on parts for the power plant.

Current I have a 340 block at the machinist for a check up for a 4.25/W5 stroker engine.
A 360 & a 5.9 in the wings slated for a 4.0 arm upgrade.
And 1 - 360 awaiting a W2 set up to be done.

In the end, what ever your happy with.
Money wise, if your pockets could use some help, and who's couldn't use some, sell the 340 and roll the money over into the 5.9.
 
rumblefish360 said:
More intake selections
More piston selections
More head selections
More rocker selections
More valve selections
More cam selections
Smaller mains = less drag, more power
(OK, I even think that's crazy but it is true though you would never feel it.)

The following can be done one way and not the other.

Head swap between LA and Magnum not a problem.
LA can use a Magnum head, Magnum can't use an LA head.
Stronger valve train set up.
LA to Magnum cam swap easier. Magnum to LA cam swap not possible OR you'll need a. Entire LA front.

I myself like the bigger bore though someone said very accurately you'll never feel or know a .040 larger engine. That's OK, the dyno will show you and the drag strip will show everyone else with all other things being equal.

But this is what I would do with it all. I may sound like a hypocrite, so here it goes, while I did t have the choice the OP has, I just recently raised a '00 Magnum 5.9 for my B body build and swapped on bolt on parts for the power plant.

Current I have a 340 block at the machinist for a check up for a 4.25/W5 stroker engine.
A 360 & a 5.9 in the wings slated for a 4.0 arm upgrade.
And 1 - 360 awaiting a W2 set up to be done.

In the end, what ever your happy with.
Money wise, if your pockets could use some help, and who's couldn't use some, sell the 340 and roll the money over into the 5.9.
Click to expand...

The orig poster has a RUNNING 360 magnum, a cam and intake swap will be far cheaper than "building" a 340, or stroked 340. I wasn't talking in the context of having to build both from scratch. I think that's what hes getting at. Both engines have advantages and disadvantages.
 
This I know and this is understood.

Please re read what I wrote and understand what I wrote.
I have both options available to me right now just as the op.

What you may have missed is that I currently have the running '00 Magnum engine in my car and I am building a stroker W5 from scratch.

He asked my opinion and got it.
Your question has been answered above.
 
1 - 5.9 Magnum installed
 

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1 - W5 being built
 

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Intake
 

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If the expense of slipping in a 360 crank into a 340 is to much for YOU, then that's OK.
The OP asked the question and has the parts ready to go.
So the expense is HIS.

YOU may cry all you want about expense but it is not YOUR call but the OP's CALL.

I have gone half way down this route. I have NO issue with it uike YOURSELF. Who is worried about spending his money. Which is fine.

IF, YOU don't want to spend the money on a stroker that you allready have the parts for, that's fine.
I am & im good with it.

Thanks, Rob
 
15 pac van.
Um, pardon my ignorance, but what is that?
Is that like, you can pac 15 girls into it?
If yes, I volunteer to try and be 16.Oh wait, Im 62now. Ok, erase that. Can I watch somebody else try? Oh wait, thats still pervy. Can I think about it then? Naw still pervy. Man it sucks getting old!
Lets see here,how do I delete this post?
Anyways.... what is a 15 pac van?
 
Bang for the dollar it's hard to beat adding parts to a running long or short block magnum.
But when building from scratch, while not necessarily for most builds if you have the choice 340 block wins every time, there's still ones to be found at deals. If building 2.05 plus valved heads I would definitely start with 340.
If one can't be found for reasonable funds nothing wrong with 360 obviously.
 
It is very true the bigger bore of the 340 is a advantage in the fact that the head can flow more air bolted over a larger bore, which doesn't show up on the flow bench, but it does when its bolted on the engine. If I understand the original posters question though, the whole purpose was the most economical way to make good power on a budget. So the magnum 360 wins hands down, it this particular discussion. My earlier post, was how was building a stroked 340 better in THIS situation, not in EVERY situation.......
 
This is what I read. Nothing about $$$ here except getting the engine cheap.

gliderider06 said:
Wondering what everyones thoughts are? I have a stock bored 340 that I was planning on 3.58 stroking, since I already havea 360 crank/rods etc...
Now the quandry comes in to where I just got a complete 99, 5.9l magnum for really dirt cheap from a buddy of mine, with 100,000 ish miles on it. I can get a new cam for magnum, ring/bearing it etc... and probabally make same or more HP than the 340. I already have a LA 360 in the 69 Dart now, that runs great. I just wanted to do another motor for the car and make a little more power.
What engine would you build?
Click to expand...
 
Thanks all... The 5.9 is from one of the extended vans that hold 12-15 passengers. The magnum I feel will need less machine work than the 340, which will need everything, which is cool. The heads for it need everything, but are factory 2.02. I have a 360 crank/ rods, that will need to be done to fit etc...
The magnum, already running, a roller cam, better flowing heads than the 2.02's. Now, after I pull the mag apart, it only needing a hone, bearings and some light machine work, and valve job will be a whole lot cheaper machine work wise than the 340. So, with that said, if I saved 1,000-1,500 on machine work alone, could I put that money in a good set of EQ heads? I do know someone that also has a brand new set of factory magnum heads that have never been bolted on, that could be cleaned up with some mild porting. (if he will part with them that is)
I will have to buy, for either engine an intake, complete cam kit & valve train (340 has nothing) and flexplate. I plan on leaving my current motor in the car complete except for dist, carb and pullies, which I will swap to new motor. I do hope I am conveying what I have been thinking correctly and not creating more confusion. I also think my cam choices will be from the Voodoo line of mech flat tappet (340) or hyd roller (mag), and an Eddy air gap for either motor. with the cost and work comparbles that I hopefully listed, building both similarly it will be a wash. One will need more on labor and the other on parts. I just dunno!
Thank you again!
Paul
 
Since the Magnum will be employed, (Or so it seems to me to be so) you will need a B&M flex plate to use a neutral balanced converter if you do not have the stock Magnum flex plate now.

On the cam, stay with the roller set up in the 5.9. The cams are priced in the low 300 range. Lunati sells there for around $333. Staying with the Magnum engines Hyd. roller set up is cost saving with the roller lifter advantage. Going back to a flat rapper design is stepping backwards. Just make sure you use a LA cam. Which should be no problem.

Making use of the LA front cover will allow you to use a mechanical fuel pump. This is also cost saving over a electric pump purchase.

On the engine itself from this point, it is a distributor, intake carb and headers.

This is the route I have taken myself on my '00 Magnum swap into my '79 Dodge Magnum. (Pictured prior)

In the future it will get a small cam.
If making more power is desired, I would skip the ported iron and save for a set of Edelbrock heads and roller rockers well peeped and lightly ported.
 
rumblefish360 said:
Since the Magnum will be employed, (Or so it seems to me to be so) you will need a B&M flex plate to use a neutral balanced converter if you do not have the stock Magnum flex plate now.

On the cam, stay with the roller set up in the 5.9. The cams are priced in the low 300 range. Lunati sells there for around $333. Staying with the Magnum engines Hyd. roller set up is cost saving with the roller lifter advantage. Going back to a flat rapper design is stepping backwards. Just make sure you use a LA cam. Which should be no problem.

Making use of the LA front cover will allow you to use a mechanical fuel pump. This is also cost saving over a electric pump purchase.

On the engine itself from this point, it is a distributor, intake carb and headers.

This is the route I have taken myself on my '00 Magnum swap into my '79 Dodge Magnum. (Pictured prior)

In the future it will get a small cam.
If making more power is desired, I would skip the ported iron and save for a set of Edelbrock heads and roller rockers well peeped and lightly ported.
Click to expand...

All good info... The roller cam is a win/win for the magnum, that alone is a big plus to me personally. If you are going to run a 727 and can get the flexplate with the magnum you can use that by sloting one hole slightly if I remember correctly.
 
The 360 roller cam will cost more than the 340 cam and lifters. The Edelbrock Magnum intake has the straight fitting for the bypass hose for serpentine belt setups. Do you have all those brackets?
I say build the 340 for all the reasons that Rumblefish stated. Plus the car is worth more with a 340 than it is with the 360.
 
I just wanna say, making use of the 5.9 is certainly a good way to go and get it done quick if it is in good shape. Ain't nothin wrong with that.

Bob makes a good point on cam cost. The advantage of the roller cam is small at this level but an advantage it is and more power is the result. A good trade off on dollars vs. power return IMO. Doing the same to a non roller engine will incurs the additional expense of roller lifters. (Ouch!)

I honestly don't see ether choice a bad one.
 
Magnum of course; they are plentiful and come with modern upgrades; 340 is nostalgia wrap it in plastic and handle with kid gloves. BTW, who decided it was a good idea to start another 360 vs 340 thread? Stroker or not, this horse is dead....
 
I love it when people debate Wich mopar engine is better ,build what you want it doesn't matter their both mopars! You will be happy no matter what! At least your not build a stupid cookie cutter LS garbage!
 
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