318 or 360 - What to Build

[1973_Swinger]

Hello FABO,

I'm restoring a 1973 Dodge Dart Swinger.. I'm getting to the stage where I need to start planning/thinking about the power plant. factory 318 car but I also have a 360 in the shed.

the specs for my build:

• 1973 A-body Dart
• 318 or 360 motor
• I have a purple shaft cam that came with the 360 purchase
• I have 4.10 gears in the back with torsen helical locker
• I have P315/35R17 rear tires (I tubbed the rear)
• I have 727 transmission (I will likely do a shift improvement kit)
• I'm at 400m ASL (1300ft)
• This will be a street runner with minimal strip use with highway driving to and from my house to the city
• I like the lopey sound but don't want it to barley idle lol

I know the 360 will need overhauled as I have not heard it run and it has been sitting for many many years

the 318 was running when pulled but that too was over 10 years ago (I have been working on this car a looooong time... lol)

I would like to know what I'm getting into with this purple shaft cam setup, should I dump money into the 318 or the 360? run the 318 stock while i build the 360??

With this purple shaft cam am i able to run factory heads.. I will want to pair it properly with an intake and 4bbl carb, high-stall torque converter ect. what should I be looking at first? am I jumping the gun on anything...?

 

[RustyRatRod]

If you HAVE the 360, build it.

 

[318willrun]

For what you are describing, the 360 is your power plant.

• Need more than "purple cam". They made a very large spectrum.

 

[Professor Fate]

Find out the specs on your cam, there should be a part number stamped on the end. "Purple Shaft" was a series of cams, not a single individual grind, so it's hard to say if it'll work for you and what it will need for springs, etc.
Off the cuff, build the 360- but tear it down first and get an idea of how much work it's going to need and what it's going to cost to get it whipped into shape. For all you know at this point it could be totally trashed inside- if so, build the 'teener.

 

[1973_Swinger]

sounds good, I will get the spec tonight on the cam.

 

[RustyRatRod]

sounds good, I will get the spec tonight on the cam.

Chop chop Hop Sing. We ain't gettin no younger. lol .....and cool avatar!

 

[Dartswinger70]

Well since the big point of debate usually is price of the core and I am assuming you have both as cores, I say build the 360.

 

[fishmens67]

I'm grasping with the same decision, do I build the 413 or the 440.
I'm strongly leaning toward the 440.

 

[1973_Swinger]

I got the 360 about 10 years ago for a couple hundred bucks with the purple cam. its likely an emissions motor.

One thing I did forget to mention.. it may be a long shot - but in the future I would really like to do a 4 speed but that's not in the budget right now (how many times has that been said on FABO...?) LOL

 

[318willrun]

I'm grasping with the same decision, do I build the 413 or the 440.
I'm strongly leaning toward the 440.

413... Dare to be different

 

[1973_Swinger]

I'm grasping with the same decision, do I build the 413 or the 440.
I'm strongly leaning toward the 440.

I guess I also have a 440 that my dad was going to put into his '38 Plymouth - but he opted out for a new gen Hemi..

I was thinking of keeping the Dart a small block car.

 

[NC Engine Builder]

Built simular, they will cost roughly the same to build. The 360 gives you "free" cubic inches. Build whatever you like.

 

[MadScientistMat]

I'd build the 360 and consider a more modern cam. Doesn't exactly sound like gas mileage is the goal here, so get as many cubes as you can.

 

[fishmens67]

413... Dare to be different

Don't you remember me telling you I'm doing a 413 stroker, the block is already square decked and bored to 4.250 and can go further, lots a meat.

 

[1973_Swinger]

I'd build the 360 and consider a more modern cam. Doesn't exactly sound like gas mileage is the goal here, so get as many cubes as you can.

ill burn as much gas as I can until the gov't requires me to swap in a few electric motors and 2,500Lb of batteries..

 

[318willrun]

Don't you remember me telling you I'm doing a 413 stroker, the block is already square decked and bored to 4.250 and can go further, lots a meat.

361 with a 4 and a quarter stroke - and a tunnel ram - solid lift with 250 duration @ 050 - Closed chamber iron heads - time for you to do a build on this site !!!

 

[fishmens67]

361 with a 4 and a quarter stroke - and a tunnel ram - solid lift with 250 duration @ 050 - Closed chamber iron heads - time for you to do a build on this site !!!

You do know I charge, don't you.

 

[273]

If both are gonna be a rebuild, I'd start with the 360 but if the 318 bottom end is ok and on a tight budget might do the 318 with 360 heads depending on the shape of everything.

 

[273]

Well since the big point of debate usually is price of the core and I am assuming you have both as cores, I say build the 360.

Notice how everyone is saying 360 when there's a reasonable choice between them.

 

[volaredon]

ill say 318.

 

[RustyRatRod]

lots a meat.

That's what she said last night.

 

[Ottmundr]

4.10 sucks on the freeway.
3.31" stroke vs 3.58" stroke.
Now imagine you're buzzing down the road at 70 mph (i have no idea what that os in Syurpean units of measurement). You will ne sitting at about 4k.
Consider that stroke again.
Personally, id say fuckit and run the 360 anyways. It is something you will want to keep in mind.

 

[Spadman]

I got the 360 about 10 years ago for a couple hundred bucks with the purple cam. its likely an emissions motor.

Your 360 could be a Magnum with better heads than an LA. Look at the dates on the block. Pull the valve covers and see if you have shaft rockers or studs. I’m assuming the 318 if original to the car is an LA but I don’t believe you said on the 360.

 

[fishmens67]

That's what she said last night.

Dream much? lol

 

[RustyRatRod]

Dream much? lol

Naw, she had double meat on a sub sammich. lol