1998 360 Magnum or 1965 273 cu in

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Coolvibes

Coolvibes

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I am in the process of slowly changing my 1965 more-doors dart 270 from a 3 speed manual to a 4 speed 833. Last week I dropped of the dismantled 273 parts at the machine shop to be measured to determine a course of action. My car's odometer says 32K miles, the machine shop owner says the internals of the engine look good / low mileage, but there was blue color on the head and block mounting surfaces indicating non-original Fel-Pro gaskets. Hmmmm.

This week I came across a claimed 100,000 miler 1998 360 Magnum from a pickup, that's been sitting for 4 years in a warehouse. Gonna look at it tomorrow. Would the exhaust manifolds from the 273 work, albeit not perfectly, on the 360? Sorry, I don't like headers.

Any foreseeable problems with the 833 gearbox and the 360? Guess I will need a new flywheel, as the 360 is currently bolted to an automatic.

I wanted to keep the car as original as possible, outside of the gearbox switch, but I don't mind better sealing engine gaskets and more cubes. I also like hydraulic lifters that don't need adjusting. Not planning on racing the car; just want a nice highway cruiser, that will be able to leave a traffic light with modern traffic. I had a 1968 Benz before that was unable to do either.

Suggestions? What would you do?

PS - the machine shop guy who is an old timer, also said the 273 has a good crank; they don't make the newer motors out of good metal anymore.
 
um
Coolvibes said:
I am in the process of slowly changing my 1965 more-doors dart 270 from a 3 speed manual to a 4 speed 833. Last week I dropped of the dismantled 273 parts at the machine shop to be measured to determine a course of action. My car's odometer says 32K miles, the machine shop owner says the internals of the engine look good / low mileage, but there was blue color on the head and block mounting surfaces indicating non-original Fel-Pro gaskets. Hmmmm.

This week I came across a claimed 100,000 miler 1998 360 Magnum from a pickup, that's been sitting for 4 years in a warehouse. Gonna look at it tomorrow. Would the exhaust manifolds from the 273 work, albeit not perfectly, on the 360? Sorry, I don't like headers.

Any foreseeable problems with the 833 gearbox and the 360? Guess I will need a new flywheel, as the 360 is currently bolted to an automatic.

I wanted to keep the car as original as possible, outside of the gearbox switch, but I don't mind better sealing engine gaskets and more cubes. I also like hydraulic lifters that don't need adjusting. Not planning on racing the car; just want a nice highway cruiser, that will be able to leave a traffic light with modern traffic. I had a 1968 Benz before that was unable to do either.

Suggestions? What would you do?

PS - the machine shop guy who is an old timer, also said the 273 has a good crank; they don't make the newer motors out of good metal anymore.
Click to expand...
um, I dont know much, but if you do use a late model 360, (or any engine that was not originally equipped with a manual) I think you will need to have the crank drilled for a pilot bearing? (or something like that)
can anyone else confirm this? OR get a whole new crank altogether.
But other than that, I cant think of much else except possible different sized ports on the intake and exhaust manifolds due to the new generation.
 
5.9 Magnum, not even a thought. But it does come with weird issues with balancing and availability with intakes.
 
............... ^^What he said ^^..............

As to exhaust manifolds; forget the 273 stuff. For a few bucks you can have some way better flowing big-port stuff.
Theoretically you could down-cam that 5.9M a lil, and make some big low-rpm torque and run some really small rear gears, and you sure as heck wouldn't need a 4-speed.
But hey, this is one place you could use the 833od, and run some bigger than usual gears, and then cut them back down to size with overdrive.

Here is my thinking on that;
The A833od has ratios of 3.09-1.67-1.00-.73od
The roadgears with 3.23s are; 9.98-5.39-3.23-2.36
With small tires around 25.5 tall (~80" roll-out), 65=2020rpm
Starter gear is 9.98 so lots of blast-off gear, and
Second is 32mph @2280 for a nice around-town cruise. If you need more power (doubtful) you can get it in First at 32=4200
So that sets the tone for the engine.
The stock cam is small enough that you can use the entire engine as is; just slam it in, hook it up, and go.
However, lol;
the 5.9M is not known for getting stellar fuel-economy. So; since your car is light enough that it will have no problem moving down the road at 65=2020;
AND the gears are all useful;
you could, if fuel-economy is/or becomes, an issue;
that stock 5.9M has enough room in the Scr for you to play with smaller cam specs;
which will give up nothing in your application, and probably make it even more fun to drive. Sorry about that long run-on sentence.
 
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Two different animals. A 360 is a low rpm high torque motor. The 273 is a high rpm screamer. The 273 will act like a normal engine till it hits 3,000 rpm and then pulls hard though 6,000 rpm like a 340. The 273 will also get you 20 + mpg cruising with 3.23 gears. I would think the exhaust manifolds would work with Magnum heads, but there will be a lot of gotcha's, including balance, motor mount bracket, timing cover and everything in front of it, and you have small wheel wells, clutch to hold a 360 with the 273 flywheel. That's what I come up with off the top of my head. My brother and I both ran 273's for decades. They are great engines.
 
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Iron manifolds of one of the jeeps are supposed to be good? The magnum pilot bearings will work but you may need to trim the input shaft length a touch, or just rough drill the back end of the crank for clearance and use the magnum pilot.
 
Id keep the 273. You can perk them up but won't have the tire shredding torque of the 360. Your wheel arches are pretty narrow for any tire back there and the 273 with its manifolds sits nice in there. You can go magnum exhaust on the 360 and clear most everything under there but you still have to make downpipes for the magnums, deal with the balance issue and clutch size as well as the intake. You could do alot to the 273 with all that 360 money.....including hydraulic lifters....heck throw the rollers in there on a 5.2 roller cam! Make a spider retainer for the lifters.
 
AJ/FormS said:
............... ^^What he said ^^..............

As to exhaust manifolds; forget the 273 stuff. For a few bucks you can have some way better flowing big-port stuff.
Theoretically you could down-cam that 5.9M a lil, and make some big low-rpm torque and run some really small rear gears, and you sure as heck wouldn't need a 4-speed.
But hey, this is one place you could use the 833od, and run some bigger than usual gears, and then cut them back down to size with overdrive.

Here is my thinking on that;
The A833od has ratios of 3.09-1.67-1.00-.73od
The roadgears with 3.23s are; 9.98-5.39-3.23-2.36
With small tires around 25.5 tall (~80" roll-out), 65=2020rpm
Starter gear is 9.98 so lots of blast-off gear, and
Second is 32mph @2280 for a nice around-town cruise. If you need more power (doubtful) you can get it in First at 32=4200
So that sets the tone for the engine.
The stock cam is small enough that you can use the entire engine as is; just slam it in, hook it up, and go.
However, lol;
the 5.9M is not known for getting stellar fuel-economy. So; since your car is light enough that it will have no problem moving down the road at 65=2020;
AND the gears are all useful;
you could, if fuel-economy is/or becomes, an issue;
that stock 5.9M has enough room in the Scr for you to play with smaller cam specs;
which will give up nothing in your application, and probably make it even more fun to drive. Sorry about that long run-on sentence.
Click to expand...

What he said! ^^^^^^^^

A manual trans usage needs to have the crank looked at on the magnum for depth issues. AJ mentions a particular 833 FWIW. I’m s an earlier unit not so commonly found. There around though.

I dropped a ‘00 - 5.9 in my ‘79 Dodge Magnum. The rest is a 727 & 3.55’s on a 245/60/15. The 3.55’s are OK, not great on the Hwy. @ high speeds like 70 mph. An OD trans is awesome here. For an automatic the A-500 (904 w/OD) would be very good and more efficient than a 727 never mind once you hit the OD gear.

I added a RPM intake, 600 AFB, 1-3/4 headers & upgraded the ignition system. P/S in an A body needs a cam P/S bracket to fit right. Excellent driver with nice pep.
 
Coolvibes said:
I am in the process of slowly changing my 1965 more-doors dart 270 from a 3 speed manual to a 4 speed 833. Last week I dropped of the dismantled 273 parts at the machine shop to be measured to determine a course of action. My car's odometer says 32K miles, the machine shop owner says the internals of the engine look good / low mileage, but there was blue color on the head and block mounting surfaces indicating non-original Fel-Pro gaskets. Hmmmm.

This week I came across a claimed 100,000 miler 1998 360 Magnum from a pickup, that's been sitting for 4 years in a warehouse. Gonna look at it tomorrow. Would the exhaust manifolds from the 273 work, albeit not perfectly, on the 360? Sorry, I don't like headers.

Any foreseeable problems with the 833 gearbox and the 360? Guess I will need a new flywheel, as the 360 is currently bolted to an automatic.

I wanted to keep the car as original as possible, outside of the gearbox switch, but I don't mind better sealing engine gaskets and more cubes. I also like hydraulic lifters that don't need adjusting. Not planning on racing the car; just want a nice highway cruiser, that will be able to leave a traffic light with modern traffic. I had a 1968 Benz before that was unable to do either.

Suggestions? What would you do?

PS - the machine shop guy who is an old timer, also said the 273 has a good crank; they don't make the newer motors out of good metal anymore.
Click to expand...
Well, I kind of think you answered your own question - partially.
  • You want to keep it close to stock.... then 273
  • You aren't interested in racing it ?? - then 273
  • You want hydraulic cam ?? You can put one in the 273 using later LA valve train (cheap and easy)
  • IF you want more power, bottom end torque, and a roller cam - then go with the 5.9.
 
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