if i build a BUDGET 360.... LA Vs Magnum 5.9

-
S

Sebambam

Well-Known Member
Joined
Aug 11, 2024
Messages
83
Reaction score
44
Location
Dallas , TX
hi Guys
i have a 74 Duster with a 318 LA in it and it didnt run in long time so my 1st approach is to get running what i have ( 318)

but eventually i want to get more Hotrod power....
Not a Racecar!
so the upgrade to the 360 Seems to be the best bet in terms of direct fit
My 318 has a 906 Trans that seems to be good and i understand that it will bolt up to both the LA and the Magnum

does the Magnum need a specific flywheel? or can i use the one of the 318 even on a Magnum ?

Further do the Motor mounts swap over from 318 to LA & Magnum?

i understand that all the accessories only swap to the LA motor
and a Junkyard the Magnum should come with its serpentine drive for accessories.

looking around i found that the LA and the Magnum 5.9 are basically same in pricing on the web or junkyards.

What would be the easier and better approach?
LA Vs MAGNUM?

i will plan on a simple R & R
reusing the Longtubes that are on the 318 ( they should fit both i think?)

Does the Oilpan? pickup of the 318 swap over to the Magnum ?
I am looking at Speedmaster Heads for either or .

in the Magnum i like the roller cam setup and could get a good cam regrind locally for under 250$ to use with the OEM roller lifters.

in the LA i would have to rely on breaking in a Flat tapped cam .

What motor carries higher compression LA vs Magnum STOCK ?

Where do i face interference with the MAGNUM accesories in a Abody ? what are the fixes ? relocation options.

The 318 has a AC and i would like to reuse the AC, can i use a "magnum" compressor on the Old 74 AC setup ? are there any tips and tricks ?


what have you guys done LA or Magnum

20240811_084135.jpg
 
360s are external balance and need their own fly wheels or flex plates. The magnum is different too. Motor mounts are the same. Intake bolts are different but plenty of good options that fit both.
 
The 5.9 Magnum is a great platform and usually more readily available in the junkyards. There’s a great forum for this and you can probably find answers to all of your questions there.
Magnum Engine Swaps
 
I own LA's but I think I would go 5.9 Magnum if I was to switch. THe roller cam would make a difference.
 
If rebuilding it matter less, if want to go hydraulic roller then last few years of LA or all magnum or need to buy retro fit lifters for older ones, if not, it don't matter, magnum generally don't have oiling hole for LA rockers so if you want to use LA heads then you need the right aftermarket rockers. The roller LA 360 is the most versatile choice but any of the can be made to work.

As for heads it's really not worth messing with stock heads, stock magnums are know to be able to make 400 + hp as is, more if some porting is done but are known to probably be cracked which generally ain't a problem for a down and dirty build but don't really want to invest too much money into them.
1.88 valve LA heads need some work to get into the 400 hp, most feel there better for all out porting and prefer there rocker gear but again can be made to work but generally better off going aftermarket especially if looking for 450 hp + and even if not better heads generally need less cam to make same hp.
 
i did a Calculation sheet for myself
i posted in another section that i have a 440MOHO 90% built already , i just wait for the heads .
in a nut shell
if i would mess with the
318 i would have round about 3500 $ in costs coming up ( incl alu heads; Not considering bearings or rings)
360 = 4400 incl buying a junkyard engine..( incl alu heads; Not considering bearings or rings)
the
440 as is right now and parts needed from here would need = 3900$ (incl. a 727 trans ; custom driveshaft)

and now the sad part
i like LS engines
and have a fresh ( all new bearings etc already and cammed )
5.3 sitting here, i did the math too
= 3700 (carbed and th350 ;custom driveshaft)

urrrghh...


I think for now i focus on making the 318 run as is .. and think about this.
 
Sebambam said:
i did a Calculation sheet for myself
i posted in another section that i have a 440MOHO 90% built already , i just wait for the heads .
in a nut shell
if i would mess with the
318 i would have round about 3500 $ in costs coming up ( incl alu heads; Not considering bearings or rings)
360 = 4400 incl buying a junkyard engine..( incl alu heads; Not considering bearings or rings)
the
440 as is right now and parts needed from here would need = 3900$ (incl. a 727 trans ; custom driveshaft)

and now the sad part
i like LS engines
and have a fresh ( all new bearings etc already and cammed )
5.3 sitting here, i did the math too
= 3700 (carbed and th350 ;custom driveshaft)

urrrghh...


I think for now i focus on making the 318 run as is .. and think about this.
Click to expand...
LS ? don't go there! :poke: :poke: :rofl:
 
Sebambam said:
i did a Calculation sheet for myself
i posted in another section that i have a 440MOHO 90% built already , i just wait for the heads .
in a nut shell
if i would mess with the
318 i would have round about 3500 $ in costs coming up ( incl alu heads; Not considering bearings or rings)
360 = 4400 incl buying a junkyard engine..( incl alu heads; Not considering bearings or rings)
the
440 as is right now and parts needed from here would need = 3900$ (incl. a 727 trans ; custom driveshaft)

and now the sad part
i like LS engines
and have a fresh ( all new bearings etc already and cammed )
5.3 sitting here, i did the math too
= 3700 (carbed and th350 ;custom driveshaft)

urrrghh...


I think for now i focus on making the 318 run as is .. and think about this.
Click to expand...
I'd look for a cheap intake and carb and mild cam get the 318 running and driving, when ready down the road swap in the 440 and sale the 318.
 
Sebambam said:
1st approach is to get running what i have ( 318)
Click to expand...
Yes, do that. Then you have some options.
  • If the 318 is in good health, you could upgrade that in the car and save some cash.
  • You could build a hotrod 360 on the side and enjoy a running car with a 318 until you have everything necessary for the swap.
  • If the 318 is toast, well the answer is half obvious, do whatever is more cost-effective... or not.
  • Order a pizza pie with pineapple toppings.
 
I have done a couple magnum swaps.
Probably cheaper than most.
I buy a truck. Rusted rotted junk for 300 to 800 bucks. Pull the engine, flex plate, starter, and anything else worth saving.
Sell any parts that you can sell of the truck quick and easy.
Scrap the rest for most of your money back.
Buy a van power steering pump bracket,use the same headers or manifolds from your 318. Buy a Chinese air gap intake,use your 318 distributor and the magnum ignition coil.
The last one I did was a truck so I used the truck pan but in the dart I used a cheap ebay car oil pan.
On the truck I used a 5.5 psi max electric fuel pump and no regulator. I used the fuel filter with the vapor line in it and I figured it would bleed off any excess fuel pressure.

Reground cam from Oregon cams and cheap pushrods from Summit make a fun little street car.

I keep harping on doing magnum swaps this way because it is just so damn cheap to make a massive power increase over an LA.
 
HankRearden said:
I have done a couple magnum swaps.
Probably cheaper than most.
I buy a truck. Rusted rotted junk for 300 to 800 bucks. Pull the engine, flex plate, starter, and anything else worth saving.
Sell any parts that you can sell of the truck quick and easy.
Scrap the rest for most of your money back.
Buy a van power steering pump bracket,use the same headers or manifolds from your 318. Buy a Chinese air gap intake,use your 318 distributor and the magnum ignition coil.
The last one I did was a truck so I used the truck pan but in the dart I used a cheap ebay car oil pan.
On the truck I used a 5.5 psi max electric fuel pump and no regulator. I used the fuel filter with the vapor line in it and I figured it would bleed off any excess fuel pressure.

Reground cam from Oregon cams and cheap pushrods from Summit make a fun little street car.

I keep harping on doing magnum swaps this way because it is just so damn cheap to make a massive power increase over an LA.
Click to expand...
A running mildly hop up magnum is the best bang for the dollar, people get too hung up on the cracked head problem. It only matters if rebuilding and generally aftermarket heads are the way to go anyways in that case.
 
Most the guy's here (unlike me) live in America I imagine a set of rebuilt magnum heads couldn't be that much ? Where if the OP wanted to could do a magnum head swap but I guess aluminum speedmasters are so cheap it generally don't make sense.
 
Prepare for the magnum heads to be cracked and have pitted and sunk exhaust valve seats. Something I didn’t realize myself before my magnum swap and ended up costing me a lot more than I thought I would spend.
 
remytherat said:
Prepare for the magnum heads to be cracked and have pitted and sunk exhaust valve seats. Something I didn’t realize myself before my magnum swap and ended up costing me a lot more than I thought I would spend.
Click to expand...
True but they still run and run good. My take is do the swap with lapped velves and new seals and the Hughes spring kit.
Later upgrade cylinder heads.
LA's are all okd and need seat and guide work by now also so in my mind that's a wash between LA and magnum engines.
 
273 said:
Most the guy's here (unlike me) live in America I imagine a set of rebuilt magnum heads couldn't be that much ? Where if the OP wanted to could do a magnum head swap but I guess aluminum speedmasters are so cheap it generally don't make sense.
Click to expand...
About 700 bucks for rebuilder type stuff off ebay with free shipping.
I doubt a local machine shop would be any cheaper.
I wasn't aware speednaster was doing magnum heads.
 
First off, get your terms right. There is no "906 transmission". It's likely a 904. To answer your question, it's always easier and cheaper to get what you have running. I'd stick with the 318 for now and maybe try to score a 5.9 Magnum to work on while you actually still have something to drive.
 
Don't even THINK of ruining that duster with an LS..... Get your head out of the gutter
That 318 can be a respectable cruiser ... Don't discount it.....
 
If the car has been off the road for a long time, there will be way more to address, than a bigger engine.
Brakes, steering, fuel system, lights, wiring etc.
Get the car running and safe to drive down the road, than look into what you want by then. The un-seen stuff will nickel and dime you to death.
 
RustyRatRod said:
First off, get your terms right. There is no "906 transmission". It's likely a 904. To answer your question, it's always easier and cheaper to get what you have running. I'd stick with the 318 for now and maybe try to score a 5.9 Magnum to work on while you actually still have something to drive.
Click to expand...
thanks for pointing out the Typo...fixed
 
sireland67 said:
If the car has been off the road for a long time, there will be way more to address, than a bigger engine.
Brakes, steering, fuel system, lights, wiring etc.
Get the car running and safe to drive down the road, than look into what you want by then. The un-seen stuff will nickel and dime you to death.
Click to expand...
I am aware if it... and yes tehre will be stuff..
however i was asking specific for the engine parts since that is where i need expertise , and not the brakes suspension etc.. thanks
 
You must log in or register to reply here.
-

Back
Top