Engine & Transmission Compatibility

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Rustyfish

Rustyfish

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I have a '65 Dart with a very tired and smokey 273 Charger engine. It is mated to its original 4 speed. I have a line on a cheap low miles '90 5.2 from a truck. I'm wondering if there are any challenges mating the 1990 318 to the original 833. All help appreciated. Thanks
 
A few, perhaps. You will need the flywheel from a 5.2 Magnum as they are different in the crank register area. You will need the oil pan from the 273......and I think it will fit. Maybe another more Magnum knowledgeable will confirm that. If you plan on staying carbureted, you will need an intake manifold for the 5.2 as they are different in the intake manifold retaining bolt area. The early engine has a different intake bolt angle than the later. Of course you will need to figure out what to do for accessory brackets. I would try to get everything from the Magnum and go serpentine. That will require an A/C delete pulley unless you plan on using the compressor with the Magnum. I believe the motor mounts are the same.....but I'm not certain. Something stands out in my mind about a possible difference there.......none of the differences however are deal breakers and are easily worked around. Many people have done the swap.
 
RustyRatRod said:
A few, perhaps. You will need the flywheel from a 5.2 Magnum as they are different in the crank register area. You will need the oil pan from the 273......and I think it will fit. Maybe another more Magnum knowledgeable will confirm that. If you plan on staying carbureted, you will need an intake manifold for the 5.2 as they are different in the intake manifold retaining bolt area. The early engine has a different intake bolt angle than the later. Of course you will need to figure out what to do for accessory brackets. I would try to get everything from the Magnum and go serpentine. That will require an A/C delete pulley unless you plan on using the compressor with the Magnum. I believe the motor mounts are the same.....but I'm not certain. Something stands out in my mind about a possible difference there.......none of the differences however are deal breakers and are easily worked around. Many people have done the swap.
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Pretty sure this is an LA motor, not a magnum. Didn't the magnums come out in '92?
 
rustyfish said:
Pretty sure this is an LA motor, not a magnum. Didn't the magnums come out in '92?
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Then it's a 318. When did they call an LA a 5.2? Never to my knowledge. Then the only thing I think you need to tend to would be pretty much the flywheel and oil pan I believe.
 
A '90 is not a Magnum, it's a roller LA.
It's neutral balance, so you may be able to make the flywheel work- I'm not 100% sure, but I recall the 273 having a smaller crank register (OD). You may be able to have your flywheel bored to the later diameter or find a later 273 flywheel to bolt up.
All the 273 front end parts will bolt right up, including timing cover and accessories, you'll just have to re-mark your balancer.
'65 and earlier intake manifolds won't fit '66 and later LAs.
 
Oh, and you'll also need to use the 273's (or 318 passenger) oil pan, pickup, and dipstick.
You'll basically be swapping just the long block- even your 273 motor mounts/brackets should bolt right up.
 
I would use the later flywheel. Bigger clutch capacity. I believe the 65 bellhousing is a direct fit. The sneaky scalloped 10.95 clutch and pressure plate might fit it.
 
Check the alignment dowels for the bellhousing. I believe auto is different from four speed. I had a vibration issue that drove me nuts. Turns out the dowels were from a 4 spd not auto . Or wrong offset. I can't remember now it was back in 1985.
Bellhousing Hardware
 
I'm mostly concerned right now with mating with the transmission. I've got all the other parts from 2 other 273 spares minus the later crank register. Thanks
 
Kendog 170 said:
Check the alignment dowels for the bellhousing. I believe auto is different from four speed. I had a vibration issue that drove me nuts. Turns out the dowels were from a 4 spd not auto . Or wrong offset. I can't remember now it was back in 1985.
Bellhousing Hardware
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That's certainly important to get right, but that's the first I ever heard manual and auto were different. @Oldmanmopar you ever seen that before?
 
RustyRatRod said:
I would use the later flywheel. Bigger clutch capacity. I believe the 65 bellhousing is a direct fit. The sneaky scalloped 10.95 clutch and pressure plate might fit it.
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The '65 bellhousing used the little 122 tooth 9.5 flywheel. Brewers used to offer the bigger "cheater" clutch that would fit, but I don't see it listed anymore, maybe I'm just missing it. They do offer custom flywheel/clutch combos from Ram that fit the 122 bellhousing, but a bit pricey. If you try to use the later 130t. flywheel, you'd have to get the later bellhousing too. Which means a modified clutch linkage, which you can do yourself or buy from Brewer's.
 
I think the guys have covered most everything but make sure the crank on your replacement engine is drilled for the pilot bearing for your manual transmission. Not all cranks all were drilled for it..
 
Kendog 170 said:
They probably aren't maybe just had offset dowels causing the issue. As I said I can't remember .:BangHead:
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That's just something I don't know and have never thought of. That old mopar geezer will know. lol
 
RustyRatRod said:
That's certainly important to get right, but that's the first I ever heard manual and auto were different. @Oldmanmopar you ever seen that before?
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Dowels in blocks are all the same location from auto to stick. Some are not correct but it has nothing to do with the transmission. The crankshaft not being drilled on some engines is a difference between auto and stick engine. And even if the auto crank is drilled it is not sized for the bushing. NAPA use to sell two different outside diameter bushings . I don't know if they still do.
 
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