67 Barracuda 273 to 360 Conversion

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Jim910

Jim910

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Hello,

I own a 1967 Barracuda Formula S with a 273 engine with a 4 speed manual transmission and I am considering upgrading to a 360 Crate engine from Tristar Engines. Anyone have any experience them?

Also, if I move forward with this, what issues am I looking at? Is it a direct swap?

Will all of the components from my 273, alternator, water pump, power steering pump, fuel pump, ect. bolt onto the 360.

Will there be any clearance issues between the fan and the radiator? Right now I have a Griffin dual core radiator and the clearance is pretty tight.

Will I need to replace the fuel line with a larger diameter. Will I need an inline fuel pump?

I plan on replacing the clutch and any associated components at the same time.

So far the only thing I know is that the motor mounts are different.

I'm early in the planning stages of this and I want to get it right.

Right now I have the funds so if I move forward I want to do it right, so any and all advice will be greatly appreciated.

Thanks.
 
There are quite a few changes that have to be made. The 273 is internally balanced. What has been done to the 360 you're buying? Is it internally or externally balanced? If external, you'll need to figure what you're going to need for flywheel. You also will need an oil pan that will fit a 360 and your K-member/steering linkage. Swap over the front end of your 273 to the 360 so you can use your pulleys, fan, waterpump, etc. I'd swap in the timing cover too just keep it stock looking and not have to play with timing mods other than remarking the 360 balancer. What heads, intake, carb, and exhaust will you be using? Mismatching those can have performance issues.
 
Jim910 said:
Hello,

I own a 1967 Barracuda Formula S with a 273 engine with a 4 speed manual transmission and I am considering upgrading to a 360 Crate engine from Tristar Engines. Anyone have any experience them?

Also, if I move forward with this, what issues am I looking at? Is it a direct swap?

Will all of the components from my 273, alternator, water pump, power steering pump, fuel pump, ect. bolt onto the 360.

Will there be any clearance issues between the fan and the radiator? Right now I have a Griffin dual core radiator and the clearance is pretty tight.

Will I need to replace the fuel line with a larger diameter. Will I need an inline fuel pump?

I plan on replacing the clutch and any associated components at the same time.

So far the only thing I know is that the motor mounts are different.

I'm early in the planning stages of this and I want to get it right.

Right now I have the funds so if I move forward I want to do it right, so any and all advice will be greatly appreciated.

Thanks.
Click to expand...
There's a number of things you'll have to deal with.
1.) The motor mount brackets are slightly different, but can be made to work with the 360 very easily.
2.) The 360 oil pan is different from the 273/318 pans.
3.) The flywheel is balanced differently on the 360. You will either need to source the proper 360 flywheel or have the 273 unit rebalanced.
4.) The 273 harmonic balancer is also weighted differently from the 360, but maybe that comes with the new crate motor.
5.) By "all of the components" fitting, that depends on a few things. The water pump changed in '70 from the earlier iron one with a driver's side inlet to the later (which includes all 360s) aluminum pump with a passenger side inlet. This means that in order for you to use your 273 water pump and radiator you will need to also swap the timing cover, which also moves your timing marks to the side opposite of the water pump inlet so it is visible. You will also need to re-mark your 360 harmonic balancer to correctly work with the older cover. Then all of your existing accessories will bolt right up. Doing this will leave your radiator clearance unchanged. Using the later pump (which is also an inch or two deeper) will reduce your clearance, if any remains- your pullies will change and your accessories will change.
6.) The 273 exhaust manifolds will be pretty restrictive on a warmed-over 360, but useable in a pinch. Consider finding some later 340/360 A body manifolds at a minimum, or headers.
7.) Your 5/16 fuel line should be sufficient, provided it is clean and unkinked. A mechanical fuel pump will also work without having to switch to an electric. HOWEVER, this is pretty dependent on how your particular engine is built- I'm assuming a mild street build.
There will always be other little odds and ends to deal with.

I personally haven't heard of TriStar, and can offer no comments on them. However, consider Blueprint Engines- they are supporting members here and have a stellar reputation.

Good Luck!
 
The timing cover doesn't HAVE to be changed. You can just ignore the driver's side timing indicator and bolt your 273 indicator in the same manner as your 273 and remark the 360 balancer. I just like doing it for a cleaner look and so there is no confusion as to which timing marks to use.
 
No good can come from swapping a timing cover on a assembled motor unless you have to do it. Might even affect your warranty. Certainly would be contentious if you have an oil leak
 
Thanks, I will definitely check out Blueprint Engines. outQUOTE="Professor Fate, post: 1973437059, member: 58179"]There's a number of things you'll have to deal with.
1.) The motor mount brackets are slightly different, but can be made to work with the 360 very easily.
2.) The 360 oil pan is different from the 273/318 pans.
3.) The flywheel is balanced differently on the 360. You will either need to source the proper 360 flywheel or have the 273 unit rebalanced.
4.) The 273 harmonic balancer is also weighted differently from the 360, but maybe that comes with the new crate motor.
5.) By "all of the components" fitting, that depends on a few things. The water pump changed in '70 from the earlier iron one with a driver's side inlet to the later (which includes all 360s) aluminum pump with a passenger side inlet. This means that in order for you to use your 273 water pump and radiator you will need to also swap the timing cover, which also moves your timing marks to the side opposite of the water pump inlet so it is visible. You will also need to re-mark your 360 harmonic balancer to correctly work with the older cover. Then all of your existing accessories will bolt right up. Doing this will leave your radiator clearance unchanged. Using the later pump (which is also an inch or two deeper) will reduce your clearance, if any remains- your pullies will change and your accessories will change.
6.) The 273 exhaust manifolds will be pretty restrictive on a warmed-over 360, but useable in a pinch. Consider finding some later 340/360 A body manifolds at a minimum, or headers.
7.) Your 5/16 fuel line should be sufficient, provided it is clean and unkinked. A mechanical fuel pump will also work without having to switch to an electric. HOWEVER, this is pretty dependent on how your particular engine is built- I'm assuming a mild street build.
There will always be other little odds and ends to deal with.

I personally haven't heard of TriStar, and can offer no comments on them. However, consider Blueprint Engines- they are supporting members here and have a stellar reputation.

Good Luck![/QUOTE]
 
Yeah, looks like a 5.9 Magnum shortblock with an LA timing cover, flat tappet cam. At least it already has a pass. car oil pan. Anyone's guess what the balance is at this point- external magnum, external LA, or internal...
 
Thanks everyone for your advice. I have a lot to sort out and ask of the Tristar engines. A couple of additional questions.

This is a complete, warranted engine so I wouldn't want to change the timing cover but if I can get Tristar to install a pre 1970 timing chain cover during the build then will I be able to use my current water pump and all the accessories that bolt to it, thus maintaining my fan clearance to the radiator?

I would assume that they could also install the correct fitting oil pan also during the build?

The engine comes balanced so if I have to I will purchase a new flywheel as part of the clutch package.

The engine is making 350 hp / 410 lb/ft so should I be good with my existing fuel line and a mechanical fuel pump? The fuel lines have been replaced by the previous owner.

I haven't yet called Tristar Engines. I wanted to reach out here first so that I would have the advantage of all of your much appreciated knowledge and advice, making me better informed to ask them the right questions.

I checked out Blueprint engines and they only show stroker engines, but I'll give them a call.

Thanks again everyone.
 
If it is a magnum, will it take a mechanical fuel pump? You need to ask.

No need to change the timing cover, you will need the one on there to match the 360 timing marks on the balancer. All the 273 stuff will bolt right up.

If I were you, I would do blueprint engine. You get what you pay for.
 
Mike69cuda said:
If it is a magnum, will it take a mechanical fuel pump? You need to ask.

No need to change the timing cover, you will need the one on there to match the 360 timing marks on the balancer. All the 273 stuff will bolt right up.

If I were you, I would do blueprint engine. You get what you pay for.
Click to expand...

Thanks, I will definitely talk to them about doing a milder more street friendly build.
 
If they're supplying an LA timing cover, it will work with your 273 parts. Most all car oil pans will fit your '67 A-body, but, I'd find out from them the particulars on it to verify. There is no off the shelf flywheel for that application. You'll have to have your 273 flywheel balanced for that engine, or you would have to change to a later aluminum bell housing, dust covers, get a 360 car flywheel, and modify/change the clutch linkage to get it to fit. The fuel lines and mechanical pump (assuming the engine comes with a fuel pump eccentric on the cam) should work fine for a street engine.
 
Thanks for the info. If you don't mind me asking, what is involved in balanceing my 273 flywheel for that engine? Is that something that has to be done while it's attached to the engine? Is so I wonder if the engine builder could provide a new 273 flywheel, balance it while on the dyno and ship it with the engine?
cudamark said:
If they're supplying an LA timing cover, it will work with your 273 parts. Most all car oil pans will fit your '67 A-body, but, I'd find out from them the particulars on it to verify. There is no off the shelf flywheel for that application. You'll have to have your 273 flywheel balanced for that engine, or you would have to change to a later aluminum bell housing, dust covers, get a 360 car flywheel, and modify/change the clutch linkage to get it to fit. The fuel lines and mechanical pump (assuming the engine comes with a fuel pump eccentric on the cam) should work fine for a street engine.
Click to expand...
 
Jim910 said:
Thanks for the info. If you don't mind me asking, what is involved in balanceing my 273 flywheel for that engine? Is that something that has to be done while it's attached to the engine? Is so I wonder if the engine builder could provide a new 273 flywheel, balance it while on the dyno and ship it with the engine?
Click to expand...
Are new flywheels available? I haven't tried to find one lately. I would ask the engine builder what they recommend. If they've internally balanced their engine, you should be able to use your 273 flywheel as-is. They may want you to ship your flywheel to them so they can balance it if it's externally balanced.
 
cudamark said:
Are new flywheels available? I haven't tried to find one lately. I would ask the engine builder what they recommend. If they've internally balanced their engine, you should be able to use your 273 flywheel as-is. They may want you to ship your flywheel to them so they can balance it if it's externally balanced.
Click to expand...
Brewer's Performance seems to have it covered. They sell new and reconditioned flywheels and they have this kit for converting to an externally balanced 360 crate engine.
Brewer's Performance - Mopar A833 4-Speed Transmission and Component Specialists
But I'll definitely check with the builder.
 
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