help with 273

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tandpr

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I bought a 65 barracuda with a "318" in it. Come to find out through some research and actual measureing that it is a 273. I have read a bit and decided I like the idea of keeping the 273. Problems.... it measures 3.665 which I believe is .040 over. It has spun 2 rod bearings and for some reason blew the valve covers OFF the bolts that hold them down. It is a 2 barrel carb but it has solid liftes. So is it that commando bit?

Is it safe to have the crank ground and reuse? Can I go commando with this motor? (just buy a cam/flat tops/4 barrell intake and carb?)

Would it be better/cheaper/easier to just find a 318 and plop in?

I like the nostalgia of the 273 but to be realistic, I want this car to have some pep without putting 5 grand in the motor.

Any help is appreciated. I plan on going through this whole car and was hoping on some experienced advice from a cool forum :)
 
Welcome aboard! You came to the right place, now be patient and wait for your answers.
 
You're going to get all sorts of answers. Some will say rebuild the 273, some will say find a 318, and others will say go with a 360, as they are all small blocks and will bolt into your car without too much difficulty.

All '65-67 273's had solid lifters...2 barrel or 4 barrel. "Commando" is the name for the 4 barrel engine. Main differences between "standard" and "Commando" engines are: 4 barrel AFB carb, cast iron 4 barrel intake, dual point dizzy, hotter cam, 10.5:1 pistons, funky black-wrinkle, chrome-finned valve covers and chrome unsilenced air cleaner.

273 keeps the originality of your car.

318's are plentiful and cheap to find.

360's are fairly easy to find, and, for the same dollars, you're getting 87 more cubes than the 273.

So, after all is said and done, its your decision. If you want to go real fast, then the 360 is the choice. Originality...stay with the 273.

This is my opinion....you're gonna get lots different...!
 
OK. I don't need to go REAL fast, but I would like to be set back in the seat occasionally and I love the smell of expensive tire smoke :) Will the 273 give me that? I would like to keep the originality of the car but not at the cost of grandma-ing around like a little old lady.

Maybe I should have mentioned this is a 3 speed car. Thanks for the input.
 
I have a '65 Barracuda with a 327 in it. That is a +.060 318. It has plenty of "pep" with a mild cam.

Your 273 is repairable if that is your aim. Obviously a 318 is a cheaper path, with more inches. Right now you have a 2bbl intake, and a lot of machine work ahead. Looking for a running 318 would be cheaper. Finding a 318 somebody has already spent some bucks on is possible too. A 318 or 360 with a 4bbl aftermarket intake, etc in a parts car - that sort of stuff.

The dividing line is the 3.31 vs the 3.58 stroke. The 360 has the longer stroke, everything else has the shorter stroke. Stroke makes torque.

A lot depends on which way you are headed with the car. Street toy? Track toy? Daily driver? Are you going to want to mess with solid lifters? Want a later engine with roller lifters?

Which transmission are you planning to use? A 727 fits, but you will need to use an aftermarket shifter. The OE auto can be built to stand anything a small block can dish out. Or is this a 4 speed car?

The other bumps in the road with an early A body are the brakes the rear end & the exhaust...

Many of those cars had puny 9 inch drums. Some had 10 inch drums. A few had disc brakes. Brakes can be converted to discs, but OEM stuff is getting harder to find.

The rear end in most of those was a 7.5 that many will tell you is a grenade with a loose pin. So far my 7.5 is in one piece, but I plan to replace it. If you like to do donuts & burn outs the 7.5 will not last long.

The exhaust is tight with OEM manifolds. Headers will need to be fenderwell jobs, with big holes in the inner fenders. If you run iron manifolds there are a few choices, somebody here will have the part numbers.

So, fill us in on the particulars for your car, and your goals. There are many very sharp people here at FABO willing to help you.

B.
 
bohica2xo said:
I have a '65 Barracuda with a 327 in it. That is a +.060 318. It has plenty of "pep" with a mild cam.

Your 273 is repairable if that is your aim. Obviously a 318 is a cheaper path, with more inches. Right now you have a 2bbl intake, and a lot of machine work ahead. Looking for a running 318 would be cheaper. Finding a 318 somebody has already spent some bucks on is possible too. A 318 or 360 with a 4bbl aftermarket intake, etc in a parts car - that sort of stuff.

The dividing line is the 3.31 vs the 3.58 stroke. The 360 has the longer stroke, everything else has the shorter stroke. Stroke makes torque.

A lot depends on which way you are headed with the car. Street toy? Track toy? Daily driver? Are you going to want to mess with solid lifters? Want a later engine with roller lifters?

Which transmission are you planning to use? A 727 fits, but you will need to use an aftermarket shifter. The OE auto can be built to stand anything a small block can dish out. Or is this a 4 speed car?

The other bumps in the road with an early A body are the brakes the rear end & the exhaust...

Many of those cars had puny 9 inch drums. Some had 10 inch drums. A few had disc brakes. Brakes can be converted to discs, but OEM stuff is getting harder to find.

The rear end in most of those was a 7.5 that many will tell you is a grenade with a loose pin. So far my 7.5 is in one piece, but I plan to replace it. If you like to do donuts & burn outs the 7.5 will not last long.

The exhaust is tight with OEM manifolds. Headers will need to be fenderwell jobs, with big holes in the inner fenders. If you run iron manifolds there are a few choices, somebody here will have the part numbers.

So, fill us in on the particulars for your car, and your goals. There are many very sharp people here at FABO willing to help you.

B.
Click to expand...
My goal is a sweet lookin ride that I can comfortably cruise in, my wife can cruise in, and I can rip around and smoke tires occasionally. It is a 3 speed manual car. I do not intend to race it. It will not be driven daily, however it will likely see lots of weekend cruising, and sometimes a bit of tire smoking just for fun.

Thanks for your intput.
 
Just remember, 1965 273 motor had a different intake manifold and smaller intake to cyl head bolts. If you go Comando you will need to find the right cast iron 4bbl intake or the very rare aluminum piece.
 
3 speed. Column shifter?

With your goals in mind, I would look for a running 318 / 360 equipped car or pickup with an auto in it as a donor. The 318 /727 in my 65 works out well. A B&M cable shifter makes the 727 work with minimal install effort.

Which brakes are you dealing with? Wife units need good brakes.

If you really like tire smoke, there is a rear end swap in your future. The 8.75 mopar is pricey, the 8.8 ford cheaper -but needs to be narrowed. Lots of ways to go, and opinions on the subject. Check the driveline forum on this one.


.
 
Welcome to FABO. Lots of us here had the same questions about their 273's.
They are fun little engines and can be built to run pretty good. 318's are cheap and easy to come by and will have as much power as a HP 273. Really the choice is yours. Keep us posted on your build and take lots of photos. We like photos. Check out my 273 build thread to give you an idea what's involved. toolmanmike
 
You'll find that the 273 is just as cheap to build as a 318 or 360. If your aim is to cruise then the 273 may be to your liking. I have two A bodies running the 273. The vert I have has a pretty reliable motor. It cruises all day long with fairly good gas mileage but at the same time it has some giddy up and go. There are some little tricks to making the 273 perform. The stock 2 barrel 273 with the steel shim gasket had an advertised CR of 8.8 to 1. With the gas available today 8.8 to 9.5 is where you want to stay. One thing to remember. That little motor is not a torque monster so if you want to lean toward performance then you'll need some gear in the butt. 273s likes to rev and the lower the rear the faster it will grab the RPMs. Nothing more fun to drive than a hot little 273 with a 4 speed and steep gears. My vert runs with the following basic combo


.030 block, flat top pistons. Everything machined to give a 9.2 CR

920 heads with cut down stainless valves, ported and polished for maximum flow and port velocity (Flow tested)

Isky E-4 solid cam

Edelbrock D4B manifold

Carter 625 Cfm carb

Stock Hipo 273 exhaust, Y pipe to tailpipe into a Flowmaster and ending in the stock Commando resonator

Electronic ignition

Push button 904 with 8 3/4 rear with 3.23 SG
 
I had a 273 and was never happy with it. It was bored 60 over, nice small cam, headers, performer intake,etc..

Grabbed a 360 in which has more cubes plus LONGER STROKE which equals more TORQUE!

Night and day difference. I'm glad I made the switch... good luck to whatever you do.
 
Mikes270dart said:
Just remember, 1965 273 motor had a different intake manifold and smaller intake to cyl head bolts. If you go Comando you will need to find the right cast iron 4bbl intake or the very rare aluminum piece.
Click to expand...

thanks for the help
 
trapster said:
Don't just try to put a crank kit in it, make sure you have all of your rods check and straightened also.

It should have the size cast into block, and it birth date also.
check here :
http://www.yearone.com/updatedsinglepages/id_info/mopar/mopar casting numbers/castingnumbers.html
Click to expand...

Thanks for the link. I will check it out. I will be getting at least 2 new rods, but was unsure if I needed to worry about the rest. Can one check strsightness by measuring side to side with dial calipers?
 
bohica2xo said:
3 speed. Column shifter?

With your goals in mind, I would look for a running 318 / 360 equipped car or pickup with an auto in it as a donor. The 318 /727 in my 65 works out well. A B&M cable shifter makes the 727 work with minimal install effort.

Which brakes are you dealing with? Wife units need good brakes.

If you really like tire smoke, there is a rear end swap in your future. The 8.75 mopar is pricey, the 8.8 ford cheaper -but needs to be narrowed. Lots of ways to go, and opinions on the subject. Check the driveline forum on this one.


.
Click to expand...

Yes colum shift. Havenot explored brakes yet but recognize the wife to brake ratio :)

8.8 is easy to come by here. We have narrowed rear ends before so that may be a swap. Since i was primarily a ford man I know th 8.8 fairly well and think it is a pretty good unit.
 
toolmanmike said:
Welcome to FABO. Lots of us here had the same questions about their 273's.
They are fun little engines and can be built to run pretty good. 318's are cheap and easy to come by and will have as much power as a HP 273. Really the choice is yours. Keep us posted on your build and take lots of photos. We like photos. Check out my 273 build thread to give you an idea what's involved. toolmanmike
Click to expand...

Thanks I will scope that out. And wifey is takin build pics, I will attempt to keep you alll posted on progress or regress which ever the case may be
 
mullinax95 said:
I had a 273 and was never happy with it. It was bored 60 over, nice small cam, headers, performer intake,etc..

Grabbed a 360 in which has more cubes plus LONGER STROKE which equals more TORQUE!

Night and day difference. I'm glad I made the switch... good luck to whatever you do.
Click to expand...

That is what I am afraid of. Build the little motor and then kick myself cause it doesn't satisfy me. Guess I could always build another car and just cruise the 273 car :)

What exhaust is on that 360? Do you use the 273 manifolds or headers? Looks as if the 273 manifold is all that will fit.
 
tandpr said:
That is what I am afraid of. Build the little motor and then kick myself cause it doesn't satisfy me. Guess I could always build another car and just cruise the 273 car :)

What exhaust is on that 360? Do you use the 273 manifolds or headers? Looks as if the 273 manifold is all that will fit.
Click to expand...

Well the 273 had Hooker headers but when I went with the 360 I bought some TTI headers which are a nice set of headers. My 273 heads was shot so I bought a used pair of 318 heads cast number "302" and ran them on the 273 for a little while. Then I grabbed up a short block 360 and put the 318 heads on it and used the intake (Performer) off the 273. I have a higher compression because of the closed chamber 318 heads bolted on the 360. I know it sounds strange to have 318 small port heads on a 360 but the velocity is outrageous. The motor is to be considered a torque monster. I love the throttle response. It starts to fade off around 5500 RPM but she is all in until that point. I might upgrade later to some nicer heads but I'm happy with it right now.
 
Here's a picture of my duster we were talking about that has the 273....
Motor is clean...
 

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For now since it has the 273.......if it were me and I wanted to drive it a little......drop a newer 318 with roller lifters. Say 92 and down with 302 casting heads. Your flywheel will bolt to it, so will the motor mounts and use the pan from the 273. This way you can drive and build the 273 if you like or pick a bigger small block or what ever while your are having fun with the car. Also don't for get that you need to use the older water pump so that you can use the radiator. Newer motors used a water pump that dumps on the other side and requires different pulley's & brackets. Can you post pictures of the motor?
 
The 273 is a "tight" motor. hard to explain, maybe it was the 3.2x rear I had in my car but it would just keep revving until I shifted the 904 manualy. I would keep the 273. EGGE sells 4bbl pistons (they are not flat-tops, they are 2 valve relief and the opposite side is raised a little) as wll as northern auto supply. The rods are stock 273/318 but make sure the rods you get replaced are full floaters. 340/360 4bbl rods are heavier and look beefier. 273/318 heads are the same. 302 heads are a nice upgrade. 65 was a break year as far as I have seen when it comes to funky heads. 64-early 65 have the odd angle 5/16 small intake bolt holes. An edelbrock Performer 318/360 can be ground to accept the early bolt hole angles, just use a good washer under the bolt. almost every 273 was solid if not all (last year may have gotten a hydro) and can be made hydro with LA lifters and the correct pushrods. The 273 lacks the bottom end torque that my friend dart4forty mentions, a steep rear, like a 3.55 or better wakes these little motors up and they rev nice so dont be afraid to show it 6+. Id keep it a cruiser. This is not the chassis to go fast easily in. Limited brakes, rear, exhaust, space in engine bay, header cost never point to these 64-66 cars as easy hotrods. Get yourself a 67 and up if you want off the shelf generic speed parts that fit.
 
I seem to have a vague memory of the pilot bearing hole in the crank being different for the early 273's vs later years. The converter pilot hub is smaller on automatics, that I found out the hard way
 
Some good discussion here. Since the 273 and 360 are the same size externally, it is possible to make a 360 look like a 273 without a lot of effort. I'm particular to the 64-65 273HP exhaust. It's the wildest sounding single ever in my book.

Simply because the 360 produces more power, I've found that people are asking more $s for an assembly than for a 318. Apart from the acquisition cost, the 360 will produce more power-per-$ than anything.

The 68-71 340 is the best power producer as it has all the goodies and high compression. However, it is scarce and expensive when found in decent condition. These things were flogged hard so there is a lot of junk out there.

5 Things that complicate LA engine building:
  1. The 64-65 intake manifold bolts are at a different angle than later years. Some aftermarket manifolds are able to accomodate the difference, most don't. It may be necessary to use later cylinder heads to be able to use the desired intake setup.
  2. All LA forged crankshafts are not created equal. The pre-68 273s used a forged crankshaft as did the 68-72 340. The 340 is balanced for the HD con rods, the 273 used the light duty rods. Balance reciprocating parts at machine shop.
  3. It is my understanding that all of the 273 forged cranks were drilled for the pilot bushing. None of the cast cranks destined for use with automatics had the pilot bushing drilled out. A machine shop can do this for you.
  4. The intake gaskets in most overhaul sets will not allow the intake to seat properly. A soft, thick gasket will correct the problem and prevent big water sprays under the hood.
  5. The driver-side LA engine motor mount is different between the 273-318 and 340-360 blocks. The third world solution is to shim the difference with flat washers. A more secure solution is available from Schumacher Creative Services.
 
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