Engine is pulled - 273 rebuild or replacement 360 crate?

[brodphish]

First the car…..1965 Barracuda

09 30 65 build date
Block casting 11 5 1965
Assembly stamp on block B273 11 19
It has the 1965 heads with the narrow bolt angle

Does this make sense for an original block? Or is it a 1966 block due the B stamp and late casting and assembly date?

The engine was pulled yesterday. We’ve found:

2 bbl pistons (same as fender tag; currently running a Qjet with an Offy 360 intake)

Already .060 over, bores need to be honed. Are .080 pistons available?

 

[273]

360

 

[brodphish]

My preference would be to do a build on this motor. Already .060 is an issue. From reading numerous posts there are issues building a 273 including. Head gaskets would be a makeshift solution.

I’m willing to have the work done but I don’t want to have $7500 in 273 that won’t run right when a 320 horse 360 is available for $3500.

 

[273]

If it's at 0.060" and needs a rebuild your looking at a new block.

 

[brodphish]

Yeah that what I was thinking. Explains why “273” would say 360

 

[413]

I'd get a late 60's 318 for it.

Dump the 60 over little one, it is done

 

[Professor Fate]

A casting date of 11-5-65 already puts it well into the 1966 model year, so it's not your original block anyway.
It most likely isn't going to take another overbore either.
If you go with the 360 or a late 318, there will be other considerations to deal with (crank pocket, motor mount brackets, etc.)
Just don't make the mistake of tossing the 273 until you have the new motor installed- you'll need parts from it to make the new engine fit (timing chain cover and timing tab, water pump, accessory brackets and pullies, linkages, etc. Maybe the oil pan/pickup/dipstick & tube if you go with a 318 or 273).

 

[junkyardhero]

that's pooched and not worth the $ and headache to rebuild.

my vote would be for a 318. it's the path of least resistance, most everything you've got can port over for the swap. some judicious choices in the build will net a reasonable amount of power for the money spent without really worrying about upgrading everything else.

 

[66fs]

Too bad you are not closer, I have a few extra 273 standard bore blocks. I even have a + .040 273 block from my 64 Barracuda you could have. What trans are you running? At this point, early 318 with thick walls and the 273 top end? Or a 360 top end? What would you want if starting from a clean slate?

 

[toolmanmike]

I love those 273's and I rebuilt the one in my 66 Dart That's a hard decision to make. I will say this, most everybody that bought a crate engine is more than happy with their purchase.

 

[ch1ll]

I just had a 1968 318 cylinder walls checked. Early year 318’s are rumored to have thicker cylinder walls, guess what? A few of them were only. 106 thick. That's arguably barely enough for a .03 overbore.

More than likely your 273 at .06 over is way overbored already. Only way to know is a sonic checked and for me that was $90.00.

Your best bet is a 318 from a reputable engine remanufacturer or a blueprint 360.
You can't rebuild an engine for the cost of the blueprint 360 and you get a warranty to boot.

 

[Illahe]

Why not take the crank and rods out of the 273 and build a mild 318. You'll have a lighter rotating assembly. If the heads are closed chamber, you should be close to 9:1 with a $1000-1200 dollar short-block rebuild. 318's are on FB marketplace for $150 bucks all the time.

 

[toolmanmike]

Why not take the crank and rods out of the 273 and build a mild 318. You'll have a lighter rotating assembly. If the heads are closed chamber, you should be close to 9:1 with a $1000-1200 dollar short-block rebuild. 318's are on FB marketplace for $150 bucks all the time.

The crank and rods are the same between the 273 and 318. The 273 pistons were lighter because the were smaller so Mopar used a heavier wrist pin to compensate.

 

[Illahe]

The crank and rods are the same between the 273 and 318. The 273 pistons were lighter because the were smaller so Mopar used a heavier wrist pin to compensate.

I was under the impression that 273 rods had thinner beams and floating pins (1618669 64-71). Vs the pressed pin 318's (72-91). The 318's I've disassembled seem to have the same rod as the 360 pressed pin. But I may be mistaken.

64-67 273 have a forged crankshaft as well. I hear there are steel crank 318's out there as well, but the four I have broken down where cast...with pressed pin rods.

 

[cudamark]

What does the crank measure? What transmission are you using?

 

[496 polara]

Beautiful car! It all depends on what you want. What will take the least amount of fab work/changes to get you there.

Anything 300 + HP should be a hoot in that thing!

 

[MOPAROFFICIAL]

First the car…..1965 Barracuda

09 30 65 build date
Block casting 11 5 1965
Assembly stamp on block B273 11 19
It has the 1965 heads with the narrow bolt angle

Does this make sense for an original block? Or is it a 1966 block due the B stamp and late casting and assembly date?

The engine was pulled yesterday. We’ve found:

2 bbl pistons (same as fender tag; currently running a Qjet with an Offy 360 intake)

Already .060 over, bores need to be honed. Are .080 pistons available?

View attachment 1716478644

360 over the 273.

You could be an oddball and use the 273 heads with bigger valves on the intake side and some Port work. It'll be a stump puller off the line and still work well to about 5500 rpm.
In other words it'll make the horsepower of a 340 cammed 360 but have a hell of a lot more torque, probably to the tune of about 60 more foot pounds.
I used those type of heads and did exactly what I mentioned above on a 340 and it made 305 horsepower and 380 ft lb of torque. Near stock 340 cam but as a solid. It was .473 lift 110lsa 227 @.050, minus lash was about .458 or .460 lift... or an honest .450 at least after rocker n geometry losses.

 

[Professor Fate]

If we're throwing out hypothetical builds to the guy, try this on for size:
Have the 273 block sleeved, and bored out to size for some decent CR 318 or even 340 std. pistons. Keep your crank and rods. Throw in a nice .450-.475 ish cam.
You get to keep your existing block and still show off the "273" casting numbers; and not have to change a darned thing to make it fit (because it's the SAME engine). But you'll absolutely confound the Bowtie and Blue Oval boys as to how a 273 just smoked them...

 

[junkyardhero]

If we're throwing out hypothetical builds to the guy, try this on for size:
Have the 273 block sleeved, and bored out to size for some decent CR 318 or even 340 std. pistons. Keep your crank and rods. Throw in a nice .450-.475 ish cam.
You get to keep your existing block and still show off the "273" casting numbers; and not have to change a darned thing to make it fit (because it's the SAME engine). But you'll absolutely confound the Bowtie and Blue Oval boys as to how a 273 just smoked them...

8 sleeves for a 273 that's not a commando? or even original to the car? no thanks.

can't see the 273 number without crawling under the car. besides, a 273 is virtually indistinguishable from a 318, 340 or 360 to most mopar guys let alone the chubby and ferd freaks. nobody would know the difference.

value for money would be a 318, mas dough and pain in the dick factor would be 360 with more power potential. but with that potential comes the added expense of having the supporting cast...

 

[cudamark]

It all depends on what you want in the end, and what your budget is. Factory stock, find an A273 block with a date code correct for your car's build date. Inexpensive, a 318 build using most of your 273 parts. Street thumper, get a 340 or 360 block and all the related conversion parts. Race car.....the sky's the limit. Looks like you already have some performance parts with the MSD box and headers.

 

[65TerrorCuda]

Just based on parts availability, you'd be nuts to do a 273 over a 360. And I'm a 273 nut

 

[cudamark]

Even then, some 360 parts for that car aren't the easiest to find either.....such as the motor mount brackets, oil pan, flywheel (if manual), torque converter or aftermarket 360 flex plate (if auto) along with the reducing bushing.....

 

[Professor Fate]

8 sleeves for a 273 that's not a commando? or even original to the car? no thanks.

can't see the 273 number without crawling under the car. besides, a 273 is virtually indistinguishable from a 318, 340 or 360 to most mopar guys let alone the chubby and ferd freaks. nobody would know the difference.

value for money would be a 318, mas dough and pain in the dick factor would be 360 with more power potential. but with that potential comes the added expense of having the supporting cast...

Oh, come on- we start throwing out hypothetical baloney builds for the guy (who even said he would prefer to build this motor), and then you have to chime in and try to be the voice of reason. You're no fun.

Granted, 8 sleeves at a c-note per hole ain't cheap, but there's no guarantee a different engine won't need work, too. What it does get you is into the realm of more readily accessible parts (I.E. pistons).
OP, all joking aside, even though you have access to a $3200 360 crate motor (I don't recall seeing it be a "Blueprint") I do think your best bet is to just find a decent 5.2 Magnum (318) to drop in. Most of these things have worn really well, and the most they need is a dingleball hone and a set of rings. Most times they don't even need that. All you'll really need to buy is 4 things: an LA360 oil pan, any of the "chinagap" 4bbl. intakes, and the crank hub bushing (if it's an automatic, a roller pilot bearing if it's a manual), and the cam snout adapter from Hughes. EVERYTHING else is easily adaptable from the 273. Your 4bbl. carb, linkage, TC cover/wp/fp (even the balancer if necessary), distributor and all accessory drives and pulleys. Bone stock cam with a 5.2 will still probably put you in just between 250-275 hp. on pump regular.
Last time I got a Magnum at the Pick 'n Pull, it was a 5.9 version for $200 on half-price day (yes, this was pre-Covid, but still...) The above parts shouldn't set you back more than $300, plus gaskets.

 

[HankRearden]

magnum 360 will make the 273 seem like a pooch. cheap also.

 

[cudamark]

magnum 360 will make the 273 seem like a pooch. cheap also.

Yup, pass everything but a gas station.....