273 or 225?

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tandart66

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Hey all,

Im trying to rebuild my ‘66 Dart and have came to yet another dilemma. My recent intentions were to rebuild the stock slant in the car, and try to hot rod it out a little bit, but now a new opportunity has risen. I found a ‘65 with a 273 that I could use as a parts car to make the swap to a v8. Is it worth the extra time and money to v8 swap the Dart or should I continue with the slant build? Any ideas would be greatly appreciated.
 
if you *really* want a V8, then at least that's a convenient way to get all the V8 specific parts for the swap.

but unless it's a commando spec or already hopped up 273 it's not gonna be all that much better than a warmed up slant, and any hot rodding to the early 273 is going to cost more than usual due to the unique heads/intake.

personally i'd spend money toward upgrades-- suspension, brakes, steering, electronic ignition, alternator/wiring updates than a wheezy V8
 
You could grab all the parts for the V8 changeover now and keep them around till you
run the numbers to rebuild the /6 or find a running magnum 5.2 or 5.9, you will get many responses to help you chose.
 
I like the sound of my slant 6.


Nice sounding Leaning Tower Of Power Rusty. I like v8's but that has a nice sound. To @tandart66, If I had a 66 (which I have) I wouldn't transplant a 65 drive train in it. I would go 66 or newer. 65 273's are different than the 66 and newer ones. The heads, intake, transmission, linkage and driveshaft are different.
 
Depends on what you want, average hot rodded na /6 probably get you 175-225 hp, V8 has way more hp potential (cylinder heads) even the 273. A warmed over 273 (225-275 hp) can make more power than most heavily built /6.
 
I'd swap it!! Especially if you have all the needed parts to do it. just my opinion.
 
IMHO: swap it. Unless you like sewing machine noises and no balls under the hood.
Now with that being said - 273 is a bit costly to build power and you can only go so far with out bags of cash…. I know, I’ve got a built 273. If I had to do it again… I’d go built 318 for the money in my 66 Barracuda.

The v8 swap is actually really easy if you buy a parts car of the same generation and all the parts are there. Center link, throttle cable, manifolds. But if the 65’ has the 64-65 heads intake bolts can be an issue.

Remember - “imho” I stated that.
Back to you original poster.
 
Having hot rodded both engines, I'd do the 273 swap in a heartbeat since you have a 273 donor car where you can get all the special V8 parts. The only problem, and not really a problem, with a 65 273 is finding an intake manifold and there are work arounds for that as well. A 65 273 should have a solid lifter valvetrain, a forged crankshaft and good heads. My 64 Barracuda 273 had the same power to weight as a stock 68 Roadrunner with 383. Try that with a slant six. That being said I love slant sixes. You can't lose either way you go.
 
Depends on what you want,
Tough decision. Cost would be #1. It all has to do with budget. Ask yourself, would I be happy with a Slant ?
Am I really a V8 guy ? Last is what plan for the future of this car ?
You can't lose either way you go.
This about sums it up. If you have not invested anything in the Slant Six engine or the parts car yet, may be the time to get out the pencil and paper and list some hard figures.
Last thing is have fun with what ever you choose.
 
IMHO: swap it. Unless you like sewing machine noises and no balls under the hood.
Now with that being said - 273 is a bit costly to build power and you can only go so far with out bags of cash…. I know, I’ve got a built 273. If I had to do it again… I’d go built 318 for the money in my 66 Barracuda.

The v8 swap is actually really easy if you buy a parts car of the same generation and all the parts are there. Center link, throttle cable, manifolds. But if the 65’ has the 64-65 heads intake bolts can be an issue.

Remember - “imho” I stated that.
Back to you original poster.
I agree 100% and having built a warmed up 273 myself very recently, I can't add anything to what @Syleng1 said except AMEN !!!!

:thumbsup: :thumbsup:
 
Hey all,

Im trying to rebuild my ‘66 Dart and have came to yet another dilemma. My recent intentions were to rebuild the stock slant in the car, and try to hot rod it out a little bit, but now a new opportunity has risen. I found a ‘65 with a 273 that I could use as a parts car to make the swap to a v8. Is it worth the extra time and money to v8 swap the Dart or should I continue with the slant build? Any ideas would be greatly appreciated.
Off topic, but if that 65 has a hood on it in decent shape, I’d buy it from you. I’m just over near Sacramento.

I’m building a 225/4 speed 65 Dart, if I wanted to go V8 I’d start with a 318 magnum from a junk yard vs the 273. JMO.

72365771352__9AA8641B-A193-4262-93ED-1152D6DC993C.jpeg
 
If you swapped in the 273, you might want to hunt down a pair of 67 of later heads because of the intake issue. Another thing to consider is the earlier 273s had a smaller crankshaft register than the later ones. Something else to consider as mentioned earlier is get a 5.2 or 5.9 and build everything on the V8 K member while you are driving the slant around.
 
If you swapped in the 273, you might want to hunt down a pair of 67 of later heads because of the intake issue. Another thing to consider is the earlier 273s had a smaller crankshaft register than the later ones. Something else to consider as mentioned earlier is get a 5.2 or 5.9 and build everything on the V8 K member while you are driving the slant around.
Early A’s use the same K member for v8 and slant. He just needs the motor mount brackets. If he goes aftermarket/Schumacher v8 mounts he won’t need the drop center link, as they raise the engine enough to clear the link.

The v8 throttle bracket and the exhaust manifolds are all he really needs from OEM, pick up a 318 magnum from the salvage yard and find a small block 904 and he is on his way.
 
Early A’s use the same K member for v8 and slant. He just needs the motor mount brackets. If he goes aftermarket/Schumacher v8 mounts he won’t need the drop center link, as they raise the engine enough to clear the link.

The v8 throttle bracket and the exhaust manifolds are all he really needs from OEM, pick up a 318 magnum from the salvage yard and find a small block 904 and he is on his way.

Or just run the 65 drivetrain as is since he will have it. Adjust the valves, set the points, adjust the timing, make sure the carb is good, and the vacuum advance is working.
 
Just another thought. I'm not familiar with the 273 at all, but it sounds like differences pre 65. I wouldn't depend on just the model year of the car with what actual 273 may be under the hood. Lots of time has passes since theses cars left the factory.
 
If you swap it, this particular combination is going to present more issues than just the heads.
Assuming that they're both automatics, the '65 is going to be a cable-shift transmission, and your '66 is a mechanical linkage trans. Which means you'd have to switch to dash mounted push buttons or swap the steering column to the cable style column shifter (depending how the donor is equipped), swap out the driveshaft since the '65 uses a ball and trunnion output, the '65 uses a different leak-prone tough to source speedo cable, etc.
If it's a stick, you'd still have to switch the driveshaft, swap over the clutch linkage mount, and cut your floor and mount a hump (if necessary for a four speed).
On the plus side, you'd be getting the V8 specific throttle cable/linkage, the correct kickdown linkage, V8 motor mounts and exhaust manifolds, drop center link if your '66 doesn't already have it, V8 radiator, larger 10" brakes, and possibly the wiring harness. If the donor is a GT you could possibly get heavier suspension and a front anti-sway bar. As well as a ready source of odds and ends... If it is a very late '65, there's an outside chance it could have an 8.75 rear end in it, too.
Not to deter you from doing the swap if you decide to go that route, but just be aware it entails more than just dropping in a motor with the right mounts...
 
How easy would the 273 to 318 swap be? Any modifications to the body/frame at all? Also lets keep in touch about the hood.
Off topic, but if that 65 has a hood on it in decent shape, I’d buy it from you. I’m just over near Sacramento.

I’m building a 225/4 speed 65 Dart, if I wanted to go V8 I’d start with a 318 magnum from a junk yard vs the 273. JMO.

View attachment 1716184603
 
273, the engine I like the best.
It’s $1000 for a clapped out wagon that hasn’t run in years. I get your affinity for the 273, but for that same money he could have more horsepower, and an engine designed to run on todays nonleaded fuel. What if the bearings are shot, or cracked heads with sunk seats? The junk yard will give you 30 days to bring any motor you buy back. Will the stranger on market place do the same if the 273/904 is shot?
 
How easy would the 273 to 318 swap be? Any modifications to the body/frame at all? Also lets keep in touch about the hood.
Easy, same motor mounts.

I know the 65 you are talking about now and unfortunately it’s a pile. Lots of rust, if you buy it I’d talk them down. Keep in touch anyway, I’m not too far from you and I’m always down to help. I’ve got my built 225 but my eyes are always peeled for V8 swap stuff.
 
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