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racepaul

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Need some thoughts here.
I have a 64 dart convertible with a /6. When I bought the car it also came with a 273 V8 2bbl motor and a 4 speed. I'm finally getting around to swap the motor and have some choices to make.
Currently the 273 block is magnafluxed and looks good, the bore needs to go 30 over. My issue is the availability of parts for the 273(pitons) and the cost of said parts. I have a 4bbl intake and carb for this motor.
Option two is I have a complete late 80's 360 available(Casting # on the block is 4179930). This motor may need a complete rebuild, but those parts are available and cost less. What I don't know is if the 4 speed I have will work and would the motor even work in a 64 Dart.
Any thoughts on what would the most cost effective route.
Thanks
Paul
 
The cost of overhauling/rebuilding a 273 vs. 360 are almost identical. The level of performance/reliability gives the 360 the edge. Cost vs. yield favors the 360. The added benefit of an early a-body is k-frame change is not necessary. Either way have fun.
 
You will probably want the larger flywheel and larger clutch and aluminum bell also not the smaller 9" clutch that came with most 273's
 
That 360 might have a roller cam in it!!! Go with that.
 
I had to go with dougs and they are around 800, but I wanted to keep the power steering. You may be able to get away with 340 manifolds for about half of that price.
 
racepaul said:
Chryslerfat is that for a TTI header? Is that the only exhaust option?
Click to expand...

Depends on if you run manual steering. Power really limits your options. Treblig a member here is working on what type of manifold can be used. The stock 273 manifolds will not seal well and choke the 360 down.
 
Go with the 360! Need 64-66 A body 273 mts & add (weld) an ear and drill a hole in the added ear to match the block ears on the one side (hold the mts up to the block & you'll see what needs to be done & it is a piece of cake). Have your machine shop drill the flywheel to convert it to external balance (they need a big drill bit & some trigonometry to convert the MP diagram). 68-70 340 HP ex manifolds & may need some light fabbing so the st col can pass by the dr mani. early A tolerances are the worst & you MAY be OK as is (mockup & go from there). manual steering with its longer column is a good plan for that and some cases shortening the coupler so it dont hit the bend in the mani will work. alum later pump for a pass side radiiator and the 273 iron pump for a dr side rad inlet nipple. I ain't done this (yet) but a manual box and a PS shorter (inner) shaft in your column then use a firmfeel extension may be a plan (anyone tried this?). You need a "392" oil pan with its matching pickup which has a sharp bend compared to the 876 pans' long sweeping bend of its pickup
 
There are lots of advantages to using the 273. Do you know what year the 273 and or transmission is? I have NOS pistons and rings I'd sell at a reasonable price. A 360 has more potential but also comes with more change, especially if one exercises that potential. Like the whole drivetrain and exhaust. A HiPo 273 will push that 64 convertible plenty fast and get good mpg.
 
Like post #11, it isn't trivial. You need a different motor bracket on one side. I think your steering linkage will hit the oil pan, though a strategic mallet blow can fix that. You can't swap a 273 or 318 pan onto a 360. Might be easiest to keep all front pulleys, accessories, and timing cover from the 273. The damper and balance weights might be an issue. For auto trannys, you need an adapter ring to fit the rear crankshaft hole. Don't know about your manual tranny, but research the throw-out bearing bore.

A 318 might be easier. I would look harder at a 5.2L Magnum engine (318 ) since that gives a roller cam, cheap fuel injection, better ignition system, serpentine belt. They were fine in trucks, so should make an A-body move fast. Much info on that. Ditto for a 5.9L, but the oil pan issue and worse mileage. Don't know what manual tranny issues would arise. Many have used both Magnum engine and auto tranny (to get 4 spd overdrive), but requires reworking the tranny tunnel in the car.

I bought a set of 0.030" over flat-top pistons for my 1965 273 for $200 on ebay. It took waiting to find them. That is ~2x normal 318 or 360 pistons. You can also buy the HiPo "domed" pistons from Egge, but >$300. I also got a 4 bbl aluminum intake, also w/ waiting (1964 & 65 are unique). If you can wait, you have more options.
 
1970Duster said:
That 360 might have a roller cam in it!!! Go with that.
Click to expand...

I agree. Screw the 273 either way. Especially if the 360 is an LA roller engine......but even if it's not, it's the better bang for the buck.
 
racepaul said:
Chryslerfat is that for a TTI header? Is that the only exhaust option?
Click to expand...

I have a set of magnum manifolds on my 273 in a 63 valiant that i got from member TREBLIG, and work great so far. I thought TTI was the only option other than stock manifolds. I still have to post pics of them for the forum :cheers::D


Jake
 
Reasons to go 273 they aren't too many.

1. If your looking to build reasonable power and mileage combo. Not that you couldn't do that with a 360 but the 273 more suited to do the job.

2. If you want to build a high Rev engine. Its a lot cheaper to do it with a 273 than try to make a 360 have a 3000-7000 powerband. Sure the 360 will make over 500 hp doing it and the 273 probably won't crack 400hp but not everyone needs 500 plus hp.

3. Kind of link to 2, I'd rather have a nasty 273 that's setup right from air cleaner to tires than a thumper cammed 360.

4. Someone that just wants to go against the grain.

The main problem with 273 other than bore size (hp limiter) is the need for deep gears about 1 ratio over what a 360 would need so a 273 would need 4.30:1 to put similar torque to the ground as a 3.23:1 360. But that's why the 273 has the gas mileage advantage cause a 360 would need low 2.??:1 gears to match a 3.23:1 273.
 
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