Need advice

-
Paul Volpe

Paul Volpe

Well-Known Member
Joined
Sep 27, 2015
Messages
47
Reaction score
18
Location
New York
IMG_0007.JPG
I have a 70 340 duster(H code) its bone stock, it has a 323 open rear. I want to wake it up just a little. thinking about a sure grip with 355 or 373 gears. I just drive it locally , cruise night, car shows usually no more than 30 to 50 miles. It runs and drives great it would be nice to have both rear tires spin any advice or experience would be greatly appreciated. Thanks Paul
 
Sounds like a plan
If your not on the highway a lot taller gears will be the most cost effective way to get where you want to be
 
3.73 is a great in between gear, a little rough on the xway at 65 mph good to 50 - 55 mph. you wont feel much difference between 3.23 to 3.55
 
I was just thinking that with a 340, a 323 gear should still make the tires spin. I can spin both rear tires with a 318 auto and 323 gears in.
 
Last edited:
Those are pretty short increments to work with!! If you want to feel the burn, jump to the 3:73, if you just want a little pep up and both tires to spin, go with the 3:55!!
 
Paul Volpe said:
View attachment 1715010749 I have a 70 340 duster(H code) its bone stock, it has a 323 open rear. I want to wake it up just a little. thinking about a sure grip with 355 or 373 gears. I just drive it locally , cruise night, car shows usually no more than 30 to 50 miles. It runs and drives great it would be nice to have both rear tires spin any advice or experience would be greatly appreciated. Thanks Paul
Click to expand...
Love the car. Great color combo. I have a 70 340 4 speed Duster and it came with a 3.91' Sure Grip rear. Its fun as hell to drive from light to light but those gears are a little steep for highway driving. I would say 3.55's are the way to go.
 
My first thought is that in 69, I had a bone stock 340 Barracuda 4 speed with 3.23 suregrip gears, and I could do a wicked burnout. I would suggest 3.55 suregrip (even though some say it isn't much of a change). If your 340 is running OK, It should smoke 'em nicely.
 
I had 3.91 in my car and it would smoke em all the way through 1st gear if I wanted, but if I eased into the throttle the tires would just spin a little and the car would launch and go like hell. Still voting for 3.73's.
 
When I swapped the 3.23 in my 69 land yacht for 3.55, it was quite noticable. I'd go 3.55. Great for the highway, and can be quite snappy from a stop.
 
Get the tune up right and that means throwing the idle ignition timing out the window.

Get it so it has 14 or so initial and 34-36 total and it will wake up the low end a LOT!!!

3.23 with those short tires should be no match for a well tuned bone stock 340.
 
I agree with Cracked - if you haven't had it tuned by someone that knows Mopars I'd do that, and then reappraise the gearing. It's a bit less money to stick a limited slip diff in the 3.23s than to build a decent 3.55 or 3.91 set.
 
I'm kinda leaning towards a bigger TC too. I like a 2800 with that factory cam. But some of the 268* cams out there need more.
But I'm also all for a decent performance tune up.
But since you are gonna need an LSD anyway, I'm liking a TC and 3.55s.In this way 65mph is still doable, with those smaller tires probably kicking out around 3000 rpm .
So that comes to; a tune, an LSD/3.55s, and a TC; probably in that order.
If you have to choose between a TC and gears, I think I would pop for a 2800TC, AND an LSD, cuz tirespin will be an issue.
I think you are on the bottom rung of a ladder that will take you straight into Mopar Mania. It starts with these little things; you know; like a little more giddy-up. Then soon the tirespin gets old so more rubber, which needs bigger rims which leads to a narrowed rear and a spring relocation. Then the engine doesn't seem to be what it could be,so in goes a cam, which needs an intake, and of course that little carb has got to go. So now the tranny goes up in smoke, and the rad can no longer keep up, and the ignition won't pull at the top. Or wait, maybe the fuel system gives up first. In any case that tranny has got to be beefed up, and then; man! it sure could use a little more off the line punch,so out comes the engine and some new taller pistons go in, and things are moving along. But on the first track day you find out the engine is kindof flat on top, so off come the heads for headwork and, man! I just gotta have a bigger cam!. And that leads to a bigger rear end, a bigger carb, and a new TC.By now things are progressing and the track official comes over and says; "I'm sorry son but you are gonna have to put a cage in this beast before you can run here again."
And so the Mania continues..................
The ladder has no top.
But the climb can be a lotta fun. May it always be fun for you!
 
AJ/FormS said:
I'm kinda leaning towards a bigger TC too. I like a 2800 with that factory cam. But some of the 268* cams out there need more.
But I'm also all for a decent performance tune up.
But since you are gonna need an LSD anyway, I'm liking a TC and 3.55s.In this way 65mph is still doable, with those smaller tires probably kicking out around 3000 rpm .
So that comes to; a tune, an LSD/3.55s, and a TC; probably in that order.
If you have to choose between a TC and gears, I think I would pop for a 2800TC, AND an LSD, cuz tirespin will be an issue.
I think you are on the bottom rung of a ladder that will take you straight into Mopar Mania. It starts with these little things; you know; like a little more giddy-up. Then soon the tirespin gets old so more rubber, which needs bigger rims which leads to a narrowed rear and a spring relocation. Then the engine doesn't seem to be what it could be,so in goes a cam, which needs an intake, and of course that little carb has got to go. So now the tranny goes up in smoke, and the rad can no longer keep up, and the ignition won't pull at the top. Or wait, maybe the fuel system gives up first. In any case that tranny has got to be beefed up, and then; man! it sure could use a little more off the line punch,so out comes the engine and some new taller pistons go in, and things are moving along. But on the first track day you find out the engine is kindof flat on top, so off come the heads for headwork and, man! I just gotta have a bigger cam!. And that leads to a bigger rear end, a bigger carb, and a new TC.By now things are progressing and the track official comes over and says; "I'm sorry son but you are gonna have to put a cage in this beast before you can run here again."
And so the Mania continues..................
The ladder has no top.
But the climb can be a lotta fun. May it always be fun for you!
Click to expand...
Aj and Max you both got me really thinking I'm sure I'll do the LCD first if I'm not happy the TC . I've had three mopars when I was a kid two darts and a charger rt. Just always missed the sound and lighting them up on occasion.
 
People will spend your money FAST for you!

Why not do the stuff that cost basically nothing but a little time that offer good results?
 
crackedback said:
People will spend your money FAST for you!

Why not do the stuff that cost basically nothing but a little time that offer good results?
Click to expand...
Your absolutely right, a good friend said the same as you about the 323 s . Just wanted some different opinions
 
a 3000 stall converter is the most bang for the buck. The car more than likely came with one as they all did. It has probably been replaced with a low stall sometime in its life. That car should turn those little tires through two gears with any ratio with the original converter. Get a converter you 'll think your driving a different car.

With the brake applied as hard as you can and without the rear wheels turning. If you floor the accelerator the tach should go to at least 3000. What ever it is would be your stall speed. Most cars I see have had 2200 converter. They were installed at transmission shops over the years because that is what they have in stock one converter fits all. These converters were used in truck 727's. and you will never get any type of performance out of the car. Not even with 410 gears. Been there with many customer cars from this site and others. Get a converter It will put a smile on your face from ear to ear.
 
You must log in or register to reply here.
-

Back
Top