360 LA motor vs. 5.9 Magnum? Other drivetrain questions

[MRGTX]

What are the pros and cons to each?

IIRC, all LA 360s had cast cranks, is that right? Is this the limiting factor for performance tuning?

What does the Magnum have for a crank?

Do people ever keep the fuel injection on the Magnum?

Is it difficult to find exhaust manifolds that work with the Magnum?

I am having trouble finding a good example of either one right now but I would appreciate any help in narrowing down the search.


IIRC, the torqueflight isn't a direct bolt up to the Magnum so is the stock Magnum transmission worth getting along with the motor? Will it bolt into an A Body ('73 Dart Sport)?

This forum has been a huge help so far. I appreciate any suggestions or information. Thanks guys!!

 

[dgc333]

Both LA and magnum engines have cast cranks. You would have to be well in excess of 500 HP to really worry about needing a forged crank.

People have completely transplanted a magnum engine and the factory EFI into other cars. It takes work and a comfort level working with the wiring. However, the stock magnum beer barrel intake creats hood clearance issues in a lot of vehicles and it is not really a perfromance piece. Better to use an aftermarket intake and EFI controller for the ease of tuning..

The exhaust ports are better than the LA exhaust port but the configuration is the same so manifolds and headers are interchangeable.

The rear of the engine is the same between an LA and magnum engine. Trannies are physically interchangeable between the two engines. The only issues is the late model computer controlled trannies require and engine controller to run them. An older 727 is a simple bolt on but if you are using a weighted troque convertor the weights need to be changed for the slightly different magnum balance.

 

[MRGTX]

Both LA and magnum engines have cast cranks. You would have to be well in excess of 500 HP to really worry about needing a forged crank.

People have completely transplanted a magnum engine and the factory EFI into other cars. It takes work and a comfort level working with the wiring. However, the stock magnum beer barrel intake creats hood clearance issues in a lot of vehicles and it is not really a perfromance piece. Better to use an aftermarket intake and EFI controller for the ease of tuning..

The exhaust ports are better than the LA exhaust port but the configuration is the same so manifolds and headers are interchangeable.

The rear of the engine is the same between an LA and magnum engine. Trannies are physically interchangeable between the two engines. The only issues is the late model computer controlled trannies require and engine controller to run them. An older 727 is a simple bolt on but if you are using a weighted troque convertor the weights need to be changed for the slightly different magnum balance.

DGC333, this isn't the first time you have provided a superb answer to one of my questions. I can't thank you enough!

Good to hear that the crank isn't necessarily a weak point.. I am not planning anything that wild so that opens options.

Assuming that one didn't want to mess with the wiring, can a regular LA intake manifold be used on a Magnum?

What is the highest RPM that you can push one of these motors with a stock bottom end?

 

[ocdart]

Believe you'll need to use a crate motor carb intake since the magnum heads are drilled for vertical intake manifold bolts.

 

[needsaresto]

Yes,an L.A intake can be used BUT; you must drill the magum heads to accept an L.A intake.

There used to be a jig available for guys to drill thier own heads,but it got sold. I dont know what happened to it after that.

 

[yellowdartdave]

The 5.9 in my Dakota R/T is relined at 4800 but will actually shift at 5100 at full throttle. These are really great torque motors (due to the beer barrel intakes) and the fact that the hydraulic roller lifters are really heavy, they are not designed for high revs. They could use stiffer valve springs but that just wears everything out quicker for little gain.
They were designed to be used in vans and pickups and they do it very well. I love to tow with mine and, when empty, have out run Hemi Rams (about a truck length to 90) so it ain't no slouch. And when the tranny slams into overdrive about 100 mph, it will really jerk your neck!
The R/T weighs in at 4300#. Imagine the combo in a 3400# Dart....
NO WAITING for the powerband.

 

[dgc333]

Assuming that one didn't want to mess with the wiring, can a regular LA intake manifold be used on a Magnum?

As needsaresto stated the magnum head uses vertical mounting bolts verse the LA using bolts perpendicular to the sealing face. Besides redrilling the heads you have a low rise dual plane available from Mopar Performance, two high rise air gap style dual planes (Edelbrock and Professional Products) and a high performance single plane from Mopar Performance that have the magnum bolting provisions. Unless you are looking for something like a 6-pak, dual quad or tunnel ram the ones available will cover anything from mild to wild.

 

[340duster]

There is also the crosswind manifold that has both the magnum and La pattern. It is a copy of the Edelbrock air gap