318 wide block parts interchange

I recently purchased a 67 Coronet that has the 318 wide block engine. The engine is shot & I feel it's pointless to mess with that power plant. I have a mid 70's 360 in the garage that was pulled from a truck that i would like to throw in it. Are any of the parts from the original wide block interchangeable with the 360 ? Specifically, the motor mounts, the exhaust manifolds, distributor, & transmission. Any input would be appreciated.

Some parts will fit and it will bolt to the original trans. A weighted 360 converter(if your trans is the later fine spline input,and it should be).Or you can use a balanced flex plate used with a neutral balance converter.Exhaust manifolds are different port spacing and don't fit.The motor mounts may fit but will need shimmed,on one side the 360 mount boss is narrower.Distributor yes it will fit.My '65 Coronet has an LA 318 where a Poly/wide block once was.It has one bell housing bolt that doesn't line up,so it is not used.Not sure if this is true on your later trans,but it poses no real issue.
RT

Trans is the original 67 unit

By later trans I meant later than my cable shifted '65 model.It should bolt to the LA 360 no problem.

Is your Poly mated to an automatic or manual transmission? What about the 360?

- EM

Both were automatics

Check the converter hub diameter, sometime around 67 they went to a bigger one, the smaller one will not fit properly without a spacer ring. 68 was big for sure and 66 was small I don't remember where 67 fits. If it is the right size you can just add on the 360 weights. Also the 904 with the small hub used a smaller input shaft in the trans so you can not just get a converter with a big hub and stuff it in.

The converter hub issue only relates to the 273, the '62-later Poly has the same crank flange as the 360 LA.

A '67 with a Poly; must be Canadian?

That's what I guessed too John. I thought 66' was the last year they were used in the US. I think they went into the 68' model year in Canada.

- EM

Motor mounts, distributor and transmission all will bolt on. IIRC there is a modification to the motor mount bracket on one side. Also timing chain cover should swap.

The block has exactly the same deck height as a 1968 318. It's just the configuration of the heads and intake manifold that make it seem farther between the valve covers.

What won't swap; heads, intake, intake manifold, exhaust manifold, harmonic damper if there is one, camshaft, pushrods, valves.

R.

There s one hole on the lower part of the bellhousing that doesn't match up. It is easy to drill a hole in the right place and thread it.

R.

The term "Wide Block" is not correct. The Poly series engine block is dimensionally similar to any 273-318-340 or 360 LA series engine.
Like DogDays wrote...."The block has exactly the same deck height as a 1968 318. It's just the configuration of the heads and intake manifold that make it seem farther between the valve covers."

Thank you

Timing chain cover is different also. On the drivers side about halfway up there is a bolt hole that is not on the LA 318's. It goes where the half moon gasket always sticks out of the cover on an LA engine...

Go look at a genuine for real pre 70 LA timing cover, not the one size fits all you posted.

That is why some people call the poly 381's a wide block.

They don't really know the LA block either.

Ahh the mystery is explained, I always wondered why LA timing cover gaskets have that extra hole on the one side, now I know!

IIRC, correct term is A engine or LA engine.

A-engine = poly heads

LA = light weight block casting/wedge head

poly refers to the combustion chamber of the heads.

wedge head refers to combustion chamber.

being called a wide block refers to having larger poly heads/VC and a wider intake which makes it wider VC to VC in the engine bay.

my 73 duster with a poly 318 was a tight fit but did fit in there. the poly steel crank is a good upgrade on LA318 builds.

the magnum also has that odd T-cover hole IIRC.

While the poly is wider at the valve covers than the wedge it's a non-issue since when headers or exhaust manifolds are installed the overall width is the same (about 26" if I remember right). Hooker SC 5204's can be modified to fit the poly/'67-up A-body.

I agree wider across the intake but outside to outside manifolds same width.

just LOOKS wider because the intake and saw tooth VC are larger to cover the rockers.

wideblock = mopar slang LOL!

I learned something today! I for sure thought it was wider.

For those unfamiliar with the 'A' engine, plenty of folks now stroking them to 400in and getting 400+hp....not bad for a simple Poly318.
They are most certainly not just scrap iron anymore....
And yes, swapping in a stock B-RB would be cheaper horsepower, just have to deal with the trans.