340 to a 360

[Jim k]

switching to a 360 in my 73 cuda. what do I need to change if anything ? engine mounts ?

 

[DrEamer]

Engine mounts are the same, the only real difference that I know of is that the 360 uses a different oil pan, and the harmonic balancer, flywheel/flex plate are unique to the 360 as well.

 

[Jim k]

No issues bolting up to my 727 trans then. Just need a new flex plate

 

[DrEamer]

No issues bolting up to my 727 trans then. Just need a new flex plate

Yes, you will need one that has the correct external balance weight for the 360. Also, you may need to check that the balance on the torque converter is correct, but others may want to chime in on that.

 

[Jim k]

Trans will be rebuilt with new converter. New to Mopars. Lot of quirks to learn. Lol

 

[DrEamer]

You may want to talk to your engine builder, he can spec everything for you as part of the build.

 

[Jim k]

Yes I need to talk to him about converter stall. Supposed to be 450 hp. Should be a beast. Well at least for me. Lol

 

[KATSAAR]

drivers side 340 motor mount will be an issue.

 

[Jim k]

More info ?

 

[Cudafor36]

Mancini racing sells a special right side motor mount. It's tougher than a stock one outta a auto store. I'd recommend that or with those kinda ponies your pushing a normal mount will last a year.

 

[Jim k]

Ok. I’m not against replacing the old ass mounts.

 

[rklein71]

I would have the engine neutral balanced so you could run the 340 flex plate and harmonic balancer. That is what I did when I built my 408 from a 5.9/360.

 

[MoParsforyears]

Buy the B&M 360 flex plate and you can run neutral balance converter what ever stall you want.

 

[Jim k]

The 360 I’m getting will be balanced if that makes a difference.

 

[KATSAAR]

is it internally or externally balanced.
you will need to know when comes time to buy a converter.

 

[DrEamer]

The 360 I’m getting will be balanced if that makes a difference.

I looked up your engine on Chris's site, and it is external balanced. Have him put on the flex plate as part of the deal, and then go with a zero/ neutral balanced converter.

 

[Rob C]

Go here —-> '70-74 E-Body Products
And then scroll down for (hopefully in stock) better engine mounts and/or a engine torque strap that holds the engine in place incase of motor mount failure.

 

[Rob C]

Engine swap step one; Find out how the engine was balanced.
If it is balanced externally/stock, then a B&M flexplate can be purchased that solves this issue. There also sfi rated.

If internally balanced, make sure you have the proper balanced up front and a zero balanced converter.

 

[Jim k]

I’ll definitely consult the builder on this. Pontiacs were easy. All the same. Lol

 

[moparlee]

I’ll definitely consult the builder on this. Pontiacs were easy. All the same. Lol

That's cuz GM's are all cookie cutter