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Discussion Starter · #1 ·
I decided to post this question here because it appears that this forum gets more looks then the ramcharger forum and I don't think there's that many differences between the RC's and the trucks anyway.

I have an 84 RC 360 / 4bbl and it's time for either a rebuild or just swap in a magnum crate engine. I did notice however, that mopar offers a reman 360 RV shortblock that they say is perfect for trucks/vans. I figured that just buying the shortblock and swapping over my existing components would be cheaper then purchasing a crate engine, but I'm not sure if it's worth it in the long run. I do like the magnum engines and it seems like everybody is swapping out their tired old "LA" engine for the magnums, but I've read that a properly built LA style block can perform just as well if not better then a magnum.

Also there is one thing that I have yet to get a clear answer for and I've looked all over. In the mopar catalog's description of the 320hp 360 Magnum Crate engine, they all say "Not for use with air conditioning". The closest thing I found to an answer was in a Chrysler performance book of mine and it said when installing a magnum engine it's possible that the A/C comp will not bolt to the engine and some fabrication may be needed to make it fit... However, I couldn't discern if was talking about swaping it into a truck or into a 70's era muscle car...

So if anybody has any advice on which route to take and if the A/C can be used with the magnum crate engines I'd really appreciate the help....
 

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if i remember right the non use A/C is because of the thermostat housing interference. But there are also a few sites that offer offset necks. The right fit is in the opinion of the person you ask. i do not need EFI and I feel pretty confident on my building skills so I went with an LA...its all in what you wish to build.
 

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I actually thought the deal with the A/C was more to do with idle issues due to the lopey cam.

On a Satellite I had I had to trim the one A/C bracket a little for clearance on the thermostat housing after I installed the Edlebrock intake. It was no big deal.
 

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Aka Force Fed Mopar
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I don't see why you couldn't figure out a way to hook up the A/C, most everything on the front of the engine is the same as an LA. If the t-stat is in the same place as a LA intake, I don't see why LA brackets and compressor wouldn't bolt up. I think they may be talking about when you're putting the crate engine into a late-model truck w/ EFI and a serpentine setup.

Which one is better for you depends on what you are looking for in an engine. The 360 RV shortblock is not gonna make the power the crate engine has. However, if you swapped in a good cam and a nice set of heads (read: ported stockers or Edelbrocks, or similar) it will make as much or more. From what I've heard about some MP engines, you might be better off that way. And it'd be about the same money, and there'd be no fitment issues w/ the A/C or anything else.
 

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4 Wheel Power Disc Brakes
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AC was used on LA engines so it shouldn't be a fitment issue.... In '79 the LA manifold went to a smaller thermostat but not as offset as the magnum. Also a shortblock doesn't have heads or manifolds so the AC issue likely caused by a cam with to low of vacumm. (Loppey.)
 

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AC was used on LA engines so it shouldn't be a fitment issue.... In '79 the LA manifold went to a smaller thermostat but not as offset as the magnum. Also a shortblock doesn't have heads or manifolds so the AC issue likely caused by a cam with to low of vacumm. (Loppey.)
He could try to install a idle kick up solenoid on the carb throttle linkage to up the idle RPM's when the A/C clutch is engaged, that would take of an idle problem due to a loppey cam. I also think (COULD BE WRONG) the T-stat housing on the Magnum is in the same spot as the LA, but the water neck is at a different angle which will interfere with the A/C compressor... But hey if there is a will there is a way!
 

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4 Wheel Power Disc Brakes
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The thermostat is in the center on an LA engine, about 2" off-center on a magnum... He could use the '84 4bbl manifold on an LA shortblock.
An idle kickup soleniod could help any stalling problem at idle. Most cars use vacumm to actuate the AC doors so low vacumm can be a problem.
 

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Doesn't one of the performace companies make a LA stle intake that is drilled to bolt and fit the magnum heads? If so he could use it or just have the LA intake tapped for the Magnum heads...

I forgot about actuating the A/C doors....not sure how you could get pass that one, maybe a small vacuum pump under the dash?
 

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Aka Force Fed Mopar
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Okay, I just went and looked at my intakes, the Magnum t-stat is offset slightly, probably even 2", but not enough to interfere I don't think, it's not any farther forward I don't think. I believe the main problem is that the LA brackets won't work because of the different intake bolt angle. Probably not too hard to get around, custom brackets or modify/bend the old ones, something of the sort. Or you could switch to the Magnum's serpentine system.
 

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exactly speed...i thought i said all that in my posts but thanks for spelling it out, sometimes i guess i am not as clear as i thought i should be.
 

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Aka Force Fed Mopar
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DiverDwnPowrRam said:
if i remember right the non use A/C is because of the thermostat housing interference. But there are also a few sites that offer offset necks.
DiverDwnPowrRam said:
the thermo is not in the same location on magnums and LA
That's what I saw :) but anyway, no biggie. It's hard to say w/o having them both in front of you. And depending on the compressor, the neck could possibly interfere.
 

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Discussion Starter · #13 ·
I actually thought the deal with the A/C was more to do with idle issues due to the lopey cam.

I had also heard it had to deal with vacum issues and a lopey cam. In any case, thanks for all the help and advice... I may just go with the shortblock and save a little bit of money if I can. Does anyone know if the RV shortblock is truly better for trucks then a regular 360 shortblock?
 

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440 and a 4 speed
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Also keep in mind...

as I was doing my '70 318 into my '87 truck, I really liked the 2 bbl intake from the early 318 design - the intake runners looked more preformance oriented - had the runners going out nice and smooth - not the wierd config of some of the others...i almost installed that one when I noticed that it wouldn't work with my '87 a/c compressor. It would obviously work with that old "two piston" dinosaur compressor because they mounted it up higher and more center of the engine...(it's always fun to say that you have 10 pistons under the hood - I have this compressor in my '76 Cordoba)

The newer style compressor is located on the passenger side front and lower to the top of the block. the relocated the water temp sending unit and there is a compressor bolt bracket near where the old style sending unit was - making the the older manifold and mounting of the newer style compressor a pain - not to mention some clearance issues with some stuff.

I then investigated the LD 340 manifold I have "laying" around - it was off a stock '70 340, and noticed that it too wouldn't work with the newer style compressor - for the same reasons...the a/c bracket interfered with stuff and wouldn't be properly bolted down. I *was* planning on using this manifold when i built the next 318....but...I like my a/c down here in Florida. I did notice a newer style edelbrock manifold will clear with no issues...so I will have to get that one instead.

so...

if you go LA style - I think you might check the manifold and your a/c compressor mounting to make sure it all works. I can say that if the water temp sending unit tap is located right at the passenger side front edge of the water jacket, and there is a flat mounting bung a few inches in from there, chances are you'll have no fitment issues with the a/c stuff.
 

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Aka Force Fed Mopar
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as I was doing my '70 318 into my '87 truck, I really liked the 2 bbl intake from the early 318 design - the intake runners looked more preformance oriented - had the runners going out nice and smooth - not the wierd config of some of the others...
It is a single plane intake, as opposed the the more common dual plane. I believe it only came on light duty trucks and cars, as my '68 D200's 210hp 318 has a dual plane. They discontinued the single somewhere around '72 or '73, I think. I know my '72 had one. I used it on the 360 I had in it for a while w/ a stock BBD, and I turned it to 6200 w/o much problem.
 

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It is a single plane intake, as opposed the the more common dual plane. I believe it only came on light duty trucks and cars, as my '68 D200's 210hp 318 has a dual plane. They discontinued the single somewhere around '72 or '73, I think. I know my '72 had one. I used it on the 360 I had in it for a while w/ a stock BBD, and I turned it to 6200 w/o much problem.


Interesting......I have two of them... Might have to hang on to them and not make them boat anchors!!!


I did look at the manifold last night, and now I remember why that it wouldn't work with my a/c compressor. one of the outlets that go to the heater core is plumbed right where the compressor would sit, so that pretty much would eliminate any chance of rigging the compressor with that manifold....which is a bummer....as i really thought that would be the better manifold to use.
 

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They came out with the single plane on the 273. Best I remember there was a notch between the left & right sides to help with low speed drivability and torque. :gr_patrio
 

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my 73 had it as well...if i remember there was something special about the ports as well...at least for the 360.
 

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1baddak
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I dont know if they have changed but when i was looking at the same thing your looking at, they told me all the crate motors are built for cars therefore i would have had to change the oil pickup and the oil pan.(no biggie). I dont know maybe thats not true anymore. this was a couple years ago. So i built mine .
 

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Aka Force Fed Mopar
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They came out with the single plane on the 273. Best I remember there was a notch between the left & right sides to help with low speed drivability and torque. :gr_patrio
I think mine is just open plenum. I'll get a couple pics here soon.
 
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