Engine Swap Help Needed: 1964 273 to 2001 5.9 Magnum 360

[texmixman]

I have been searching the forums for the last few weeks to try and get all the info necessary to make this switch. I was confident enough to pull the trigger and pick up the engine today. I am going to a manifold/carb set up, no EFI.

Here are some of the things I know I need
Intake/carb - obviously
360 car oil pan
LA oil pan gasket
Cam extension for mech fuel pump
I will use my current exhaust manifolds which I know are not ideal but will work.

Unsure about the following
What do I do about balancing?
Will my distributor from the 273 drop in?
Will the LA 273 oil pan work?
Are there any issues with my push botton torque flight that need to be addressed?

I don't know if there is anything I have missed. If anyone has any critical items i need to be aware of

 

['64 Cuda]

You'll need a 360 pan. The 273 pan won't fit a 360. You also need an oil pump pickup tube for a center sump pan. The 273 distributor should fit. I think you need a different front cover to allow you to use the mechanical fuel pump. You need to modify one of the motor mount brackets (Right side?) to make it bolt up. Check to be sure the Magnum motor has the ears for attaching the earlier style mounting brackets. I think they do but not sure. If they do, then conversion mounts should be available from Schumacher. www.engine-swaps.com I also think there is an issue concerning the transmissions and torque converters with the early trans. I know there is a B&M flexplate that allows you to use the neutral balance torque converters but I'm not sure if that's all you need with the early stuff. I'm more of a standard trans guy. This is the stuff I can think of offhand. There's probably more.

 

[texmixman]

I think you need a different front cover to allow you to use the mechanical fuel pump.

Thanks 64 Cuda. Forgot to ask about the H20 pump. I think with the serpentine belt that the water pump runs backwards on these motors. Can the pre-magnum pumps be used since the serpentine build will not be used?

 

[UOP]

You can use the LA timing chain cover and water pump, my 98 5.9 magnum is running all LA accessories and ignition (electric fuel pump though). The magnum head is a little different so the alternator bracket won't bolt up perfectly(spacing from head is a little different but holes are the same), but with some spacers and a little tweaking it'll be fine. Unfortunately B&M discontinued the magnum flexplates, as did ATI, so unless you can get lucky and find one (I haven't been able to), you will need to have the converter balance weighted for a magnum (different than LA 360). The stock magnum flexplate, even though it may have the balance weight on it, won't correctly work with the older torque converters. Magnums run a symetrical bolt pattern on the converter, where the LA converters have one bolt slightly off. I've heard of guys widening the hole to make it work (even I did it for a bit), but can't in good conscious recommend doing so.

The magnum engines were mounted in trucks differently than the older la engines, but retain the la mounting points. A magnum 5.9 block has the same mounting lugs as an la 360.

Also, your intake manifold options are a little limited. The magnum intake manifold is bolted to the heads differently, so you'll need one specifically for a magnum. Your choices are the Mopar M1 sp or dp, Edelbrock Airgap (what I'm running), or Professional Products Crosswind (similar to Airgap, but can be used on either a magnum or la engine).

Hope this helped.

 

[JoeDust451]

You can longate the one hole on the flexplate, I did this & there are no issues, but i also opened up the holes & went with the larger 7/16 bolts when i ordered my PTC converter, i feel this modification is more then safe & will hold up nicely, you really don't need to longate the hole that much, maybe an 1/8" tops.

Make sure if you buy this engine it has the flexplate on it, the later ones have the weights on them.

 

[texmixman]

Here is the new engine after lots of cleaning and painting.

 

[texmixman]

Now I am stuck. Bought a weighted torque converter thinking this would bypass the flexplate issue and still get the external balancing done. Maybe this is old news to some, but the balanced TC has 22 splines and the old 904 trans had 18 splines. It goes right into place but the car wouldn't go into gear. It couldn't activate the pump.

I need to know if I can modify a 1999 flexplate by elongating the holes to make it fit with my original torque converter. I can't seem to find anyone who makes one for a 2001 engine.

Please help if you have any ideas. I am too far into to turn around now. One option thrown out by a local tranny guy was to modify the 904 to accept and change it to a 22 spline. Didn't sound like a very cheap option IMO.

 

[LXguy]

That's what I did with my Magnum. I just wallered out the stock Magnum flexplate holes (well only one hole) to fit a zero balance regular 904 converter. Its not off by very much at all.

Works great.