3.23 or 3.55 Behind a 318

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Like someone asked, what is the application?
For my street only application;
I've had 3.55s in my Dart for a year now. With 245 60 15 tires you can't floor it under 40ish mph without lighting them up. I love it but I want a better highway cruise. I'm going to switch to 3.23. A 408 doesn't need the lower gearing anyways.
I had a '73 318 Dart a few years back. Decent power with 3.91s and 14" wheels. Stout in town, useless on the highway.
A lot of this is personal preference... we're all different in what we like.
 
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My current setup is a mismatch, but that's because the engine is coming out soon in favor of a 360. I am on the fence about a 3.580" or 4" arm. I am leaning towards the stock 3.580" because I want quick over fast. The price difference for the rotating assemblies is pretty much a wash.

  • 318
  • Edelbrock performer and 600cfm carb
  • Lunati 10200701 cam installed per instructions 256/262, 213/220 @50, lift .454/475 (keep in mind the stamped rockers don't actually DELIVER that...)
  • 4.10 gears
  • 27" tires
The little 318 runs like absolute ****, see;

What Are You Doing To/With Your Car Today?

It's a daily driver, and I am slowly upgrading things as funds and the Home Owner's Association allow, meaning that I have to do most of my work in the parking lot after work, after a 10+ hour day.
 
Ottmundr said:
My current setup is a mismatch, but that's because the engine is coming out soon in favor of a 360. I am on the fence about a 3.580" or 4" arm. I am leaning towards the stock 3.580" because I want quick over fast. The price difference for the rotating assemblies is pretty much a wash.

  • 318
  • Edelbrock performer and 600cfm carb
  • Lunati 10200701 cam installed per instructions 256/262, 213/220 @50, lift .454/475 (keep in mind the stamped rockers don't actually DELIVER that...)
  • 4.10 gears
  • 27" tires
The little 318 runs like absolute ****, see;

What Are You Doing To/With Your Car Today?

It's a daily driver, and I am slowly upgrading things as funds and the Home Owner's Association allow, meaning that I have to do most of my work in the parking lot after work, after a 10+ hour day.
Click to expand...
I prefer stock 360 stroke. 4" not needed in my opinion. Especially since you got descent gear. 3.23 or less then strocker can be better.
 
Unless you are mandated to a certain Cu.in. level as in racing, Why would you want to build a 365 over a 408?
Or in the case of a 318, why would you want a 349 over 390?
 
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SGBARRACUDA said:
Unless you are mandated to a certain Cu.in. level as in racing, Why would you want to build a 365 over a 408?
Or in the case of a 318, why would you want a 349 over 390?
Click to expand...
Building a 318/349 isn’t cheap or easy. Building 318/390 is easy, ordering the kit is pressing a button easy.

Building a 360 or 400+ is dealers choice with the 360 being cheaper, part selection dependent.

A properly built and set up 360 can burn the rubber and be very quick. It is not a slouch.

You don’t need 400+ cubes.
But you want 400+ cubes.

Bottom line, build what you want. Don’t look back. Enjoy!
 
rumblefish360 said:
Building a 318/349 isn’t cheap or easy. Building 318/390 is easy, ordering the kit is pressing a button easy.

Building a 360 or 400+ is dealers choice with the 360 being cheaper, part selection dependent.

A properly built and set up 360 can burn the rubber and be very quick. It is not a slouch.

You don’t need 400+ cubes.
But you want 400+ cubes.

Bottom line, build what you want. Don’t look back. Enjoy!
Click to expand...

Agreed.

Shorter stroke, higher revving (more noise) And I could still lie and say the 360 is just a 318.

400+ cubes is the B block. That's going to be at most a 3.915 arm for a 470, taller compression height on the piston should hypothetically lead to longer engine life over a 451.

I am going with the shorter strokes for engine longevity and lower piston speed. I figure that anything I can do to build durability and reduce potential points of failure is a good thing. Also, the shorter stroke will be better suited to the 4.10 gearing. I don't worry about burning lots of gas. There are plenty of degenerates in the bay area here who drive their Prius ****-boxes and save the gas for me.
 
SGBARRACUDA said:
I've never known a man that wants less inches!
Click to expand...

Trust me, women will complain about a longer stroke...

Alexa.png
 
I know guys that like the 408 in a truck but not so much in an A body with stock tires.
Few 408's get 20 plus mpg which is important to some guys.I just built a 372 and am
wondering how efficient it will be.We were very careful with parts selection.My stock 340
is over 20mpg driven sensibly.
 
I didn’t think big block when I wrote 400+ inches.
A 4.00 X 4.00 is more than 400 and still a small block never mind a bigger bore or more stroke that can be purchased.

You can build a 430 CID small block.

Ottmundr said:
Agreed.

Shorter stroke, higher revving (more noise) And I could still lie and say the 360 is just a 318.

400+ cubes is the B block. That's going to be at most a 3.915 arm for a 470, taller compression height on the piston should hypothetically lead to longer engine life over a 451.

I am going with the shorter strokes for engine longevity and lower piston speed. I figure that anything I can do to build durability and reduce potential points of failure is a good thing. Also, the shorter stroke will be better suited to the 4.10 gearing. I don't worry about burning lots of gas. There are plenty of degenerates in the bay area here who drive their Prius ****-boxes and save the gas for me.
Click to expand...
 
904/999 torqueflite

My transmission isn't done yet but I went with the 2.74 first gear and a 1.52 second gear in the transmission. Even if you don't know anything about transmissions
In my opinion. It's easier and cheaper to change out the transmission gears than it is the differential.

This lets you keep highway 1:1 gear.

I think a 2.94 gear with the 2.74 transmission gear will give you a 3.60 gear for take off and a 2.94 gear for highway.

There is a calculation where it shows you what it would end up as.
 
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Short stroke engines make their peak torque at a higher RPM. You need to keep that in mind when choosing a gear set. A 3.31" stroke (318 and 340) will want to spin some compared to a 3.58 (360) or a stroker. "I" would want my build to be just at the beginning of the torque peak at "whatever" cruise MPH I chose. If not, it's not going to be very efficient. Put a 3.23 or numerically lower gear set in a stock stroke 318 and it won't be very snappy at cruise speed. I would at least run a 3.55 or a 3.91 and preferably the 3.91 without an OD transmission. With the OD, then a 4.10, 4.30 or even a 4.56 will work well.
 
It's true, you don't NEED a 408 or a 4" stroke. Same can be said for many things we do. 500+ lbs torque is so much fun though!

rumblefish360 said:
Building a 318/349 isn’t cheap or easy. Building 318/390 is easy, ordering the kit is pressing a button easy.
Building a 360 or 400+ is dealers choice with the 360 being cheaper, part selection dependent.
A properly built and set up 360 can burn the rubber and be very quick. It is not a slouch.
You don’t need 400+ cubes.
But you want 400+ cubes.
Bottom line, build what you want. Don’t look back. Enjoy!
Click to expand...
 
Anyone have experience with 2.76s or 2.94s behind a commando box? I'm looking for something a little more fuel sipping, but I don't wanna be burning the clutch when I'm just around town or in traffic. I do still wanna have plenty of fun with it. So if not that, then I may be going with an a833od+ 3.55s
(Car is 2700lbs the 360 makes about 380ish hp)
 
I run 3.73 w/a518 trans and a 318. It’s in a 84 d100/150. Fun to drive and with the flip of a switch I can cruise 70 all day. That’s with a 235 tire
C6F8A383-2471-4802-8818-FD3E08D02CD4.jpeg
 
What is a “Commando box?”

SpaceDemon said:
Anyone have experience with 2.76s or 2.94s behind a commando box? I'm looking for something a little more fuel sipping, but I don't wanna be burning the clutch when I'm just around town or in traffic. I do still wanna have plenty of fun with it. So if not that, then I may be going with an a833od+ 3.55s
(Car is 2700lbs the 360 makes about 380ish hp)
Click to expand...
 
Just wondering if anyone has any recommendations. It's mostly a daily cruiser, but I've made it as light and torquey as I can. @AJ/FormS might have some input?
 
I just ran drag week with a 26.5” tire and 3:73 gear with my 410 ci LA. It was fine, car usually runs 4:10’s which is a bit much on the highway. Really depends on whats important to you? I never cared about mileage. So for me, it’s does it spin it so much it gets hot on the highway or you can hear the valve train weeping in pain. No? Than it gets the rear gear that makes it go the fastest! 4:10 at the 12.2 to 1 would have made it run to warm for my liking.
 
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