Looking to upgrade the 340/360 heads in the Duster over the winter
Don't have a lot of money to go into this build
would like a streetable combo/low buck deal so tell me what has worked for you
What I have new 750 DP, Eddy RPM, stock bottom end, slight cam
727, 3k convertor, stock tank, mech fuel pump, cheapy headers with a 8 3/4, 4.10 gear and a spool, new micky DR tires

What do you mean by stock bottom end ?? 1970 or 1972 or?? A true 11.50 street trim 340 will be a bit of a rascal on the street!

Well what the motor has now is a stock bottom end
not apposed to buying new pistons and rods but keeping the crank

It can be done but you will have to give up some more streetable to trac parts. I just sold regrettably a 71 Duster 340 stock stroke car, It ran 11.30s at 118 mph. You need a good cam with as much lift as you can fit mild ported heads lots of compression more than stock, real 10-1 or better I had close to 13-1 in mine. Lots of stall I had 5000 and 4.88 gears. If you want to run a more street than race car build the best and most you can afford then throw some juice on it and work on consistency.

I agree that an 11.50 stock-stroke 340 won't be too streetable if that is what you are after. You're gonna need to spin it up pretty good so oil system must be up to par. Shifted my old W2 combo at 7,200 with a MP .557 solid cam. I drove it on the street and it was pretty high strung. Idled at 1,100 with around 7" of vacuum. I switched from a 4.30 gear to 4.10 and it had trouble with less gear, even though it's only a small percentage change. Needed a lot of pump shot to get it moving. It was also tough to tune part throttle driving on that thing.

For the heads, a set of 'prepped' RHS or EQ iron heads by one of the regular vendors are a good bang for the buck, they will flow much better than any stock head.

Currently finishing up a new 416 build and I switched from W2s to ported RHS. No numbers yet. The W2s I had were not ported though and had 2.02 valves which are pretty pedestrian by today's standards.

Or maybe just save a little coin and buy some Eddies so you can run a little more compression and save some weight off the front end.

750 DP, RPM intake and a 'slight cam' are not gonna cut it. Also, 11.50s are more than just heads. Need more gear and converter too, like 4.30+ and at least a 3,500+ converter. Car also needs to be pretty light, like under 3,200 with driver.

Good choice for a larger budget carb could be an 850 TQ if you have the patience to mess with it. Take off the choke stuff and it flows pretty good. Find a Holley Strip Dominator intake with the spread bore opening, they can be found relatively cheap.

Only managed a 12.20 @ 110 with my old W2 340 but it was tired and had a broken piston ring in one cylinder. Maybe could have gone 11.80s if it was right. Car is under 3,200 with me in it, 4.10 gear, 904 with a low gear set, 10" 3,500 converter, 275/60/15 drag radial and Caltracs. Launching just off idle netted a 1.7 60 ft.

Hope that helps.

Streetable is all in opinion. My 360 is 11:1 KB107s, Shady Dell stage II Eddie heads, 258@.050 solid roller, 4500 converter, 3.91 gear, 830 Holley,full exhaust system, 3525lbs. It has been a best of 11.18@120.5 in good air and is very streetable in MY opinion. It will get 13-14mpg on the highway and has completed 3 drag weeks. I drive it to work, to run errands, to get groceries, it is streetable. It has a thumpy 1000rpm idle and it gets up on the converter to get moving but nothing that stops it from being street driven anywhere. Going down 20 cubes might move up the RPM range some but I don't see it having much of a negative effect on street driving.

"Don't have a lot of money to go into this build"
That may be your biggest obstacle.
You're gonna have to pull some Rs with a 3.31" stroke & you'll want quality parts to make it reliable. Your carb is little on the small side,a solid or roller cam may be needed & you'll need more converter.

I think you are basically confirming what I said - need good heads (you have Shady Dell stage II Eddie heads), larger cam (258@.050 solid roller), larger carb (830) more gear and converter (4500) though you probably can get away with slightly less gear in your car (3.91) with the few more cubes.

Streetable is an opinion sure, but you need to know how to make it work on the street. A race car is somewhat more straightforward, you choose the parts and tune it for best ET and or consistency.

Again, I had a tough time with part throttle driving, took a long time to sort it out and was very finicky. Once it's tuned right it's fine but getting there can be difficult when you have stuff designed for WOT operating at part throttle most of the time. Just a lot of trade offs for what most consider 'normal' drivability. You gotta be willing to put the time in.

I am hoping that the stroker will be more forgiving tuning-wise.

My little stock stroke 318 I think has the potential to run 11.50's. Best so far in signature.
It's 3415 with me in it. At 3200 pounds and electric water pump and fan think it would do it.
This is 10.44 compression with iron heads and dinky hydraulic cam. Shift it at 6200 and only trap at 6k. I am sure deeper gears would pick it up some, only running 4.10's with 28 tire currently, as would a more aggressive cam, but its ultra street able currently.

It can be done with some mild X heads I revved mine to 7000-7200 I had an old crane 560 lift solid all my parts were old school but I dialed the chassis and got the weight down to 2900 lbs. Gears and convertor are going to be where it goes from streetable to just radical. I ran the stock bench seat as it was better with my broken back. I miss that car pulled the front rolling on the street. Match the parts the old DC books help with parts selection as they worked. I was almost knocking on the 10s before I sold it.

Your combo is what I am looking for. I don't have to hit the 11.50 mark but it would be nice. Heads are the biggest part of the deal I think
Thanks for all the input and keep it coming

http://www.forabodiesonly.com/mopar/showthread.php?t=322365

Don't have to turn them hard to go.

My 340 was .030 over, 11.4-1, ported Edelbrocks, 236/242 @ .050, .588.592 hydraulic, Weiand X-Cellerator, Quick Fuel 750, 727, the converter flashed 5000, 4.30 gears on a 275 radial went 11.60 at 3240#.

BTW, I shifted it at 6400.

My little brothers car.
66 dart, all steel, full interior, 3350 with him.
360
Ported eddies
904
Weiand excellerator
750 Holley
10 to 1
Flat tappet
4.30 gears
11.38 at 116+

I know where there is a set of IMM ported eddies and a 4" crank just sitting...

My '71 Demon ran 7.30s-7.40s in the 1/8 w/ a pump gas stock stroke 340.
340 + .030" w/ old Speed Pro flattops. Stock bottom end otherwise.
J heads w/ mild cleanup.
Comp Cams solid flat tappet, 248° at .050", about .510" lift I believe, 108° LSA
Holley strip dominator single plane manifold, 750 holley DP
1 5/8" headers, run open
4.88 geared 8.75 and SS springs, 28x10.5 slicks
904 w/ low first gear and an unknown 8" converter

Here's a post from another board I created. I strongly disagree with such a goal makes a "rowdy" or non-street friendly combo.

Soooo, quick background: Assembled a budget 416 a few years ago, and managed to run a best lap of 10.14 @ 128, irritate a few big block guys and won a few rounds including a Mopar race at Sac. Developed a bearing issue, so after we took it down to inspect and repair the car owner decided "enough". Having a low 10 second Duster was fun, but he wanted to convert the car to a 12.0 Sportsman car (no jacket, no dated belts, no fear of a mandatory engine diaper) AND be streetable. So we made changes, and I assembled a new motor.

Back to the 3.31 stroke crank
New SCAT rods
Sealed Power hyper flat tops (calculated CR is 10.3:1)
Comp Cam Hydraulic cam, .545/.545 - 241/247 @ .050" (XE285HL)
Same RHS heads from the 416, fresh with new Beehive springs.
FAST EFI 2.0

Same 904 from the 416, had the 8" converter tightened as much as possible, but still a touch too loose for the street...Need to work on that over the winter; we'll change it to a Lupo 9.5" that's on the shelf.

Swapped out the 4.56/spool for a 3.91 and Sure Grip

Tossed the many runs old Phoenix slicks on. Hmmm, 3.91's and 29.5 tire? Isn't that the same as a 3.55/27" gear/tire combo??? We want this thing to go 12.0's not 13.0's...LOL!

In addition, the car is now 170 lbs heavier: Stereo, FULL 3" exhaust to the rear, and power windows...

A tank full of 91 octane and some octane booster and off we go to the track.

Three runs made. Never touched anything except for some Cal Track adjustments and ran a best of 11.77 @ 114. Wow...love those 340's! Footnotes:

30* total timing.

Shifting at 5000 RPM. Yes, 5,000...it is a street car after all!

Across the stripe at (go back and re-read the gear/tire height) 5,200.

Maybe next time out, we'll get "serious" and run it to 6,000 and put some more timing in it. Oh and maybe play with the tune up?? We left the EFI on the base settings...didn't touch it. But how cool...change "jets" with the touch screen with the hood closed!

Should be a truly low maintenance, fun street/strip car!


****EDIT**** Didn't realize Cracked posted the link. Sorry for the repost!

If you're already willing to buy rods and pistons, the best thing you could do is spend $400 on a 4" cast crank. It will require way less in cam, compression, heads, gear, and converter to meet your goals.

**Update: Ran the Duster in a "street" class so on went a pair of MT drag radials, 315/60/15, a good inch+ shorter than the 29.5 slicks and wont have much growth at speed.

Also removed the 2 chamber Flowmaster muffs, replacing them with quieter 3 chamber Magnaflows.

Still 5200 in the shifts, but now 5800 at the stripe vs. the 5200 with slicks.

11.49 @ 116.83 off the trailer
11.45 @ 117.40 2nd run

WOW. If we move the shift light up to 6500-ish, perhaps the little 340 will give me a .30-something...

100% streetable; have logged a couple of hundred more miles since the first outing.

Previous posts highlights:

Back to the 3.31 stroke crank
New SCAT rods
Sealed Power hyper flat tops (calculated CR is 10.3:1)
Comp Cam Hydraulic cam, .545/.545 - 241/247 @ .050" (XE285HL)
Same RHS heads from the 416, fresh with new Beehive springs.
FAST EFI 2.0

Same 904 from the 416, had the 8" converter tightened as much as possible, but still a touch too loose for the street...Need to work on that over the winter; we'll change it to a Lupo 9.5" that's on the shelf.

Swapped out the 4.56/spool for a 3.91 and Sure Grip

Tossed the many runs old Phoenix slicks on. Hmmm, 3.91's and 29.5 tire? Isn't that the same as a 3.55/27" gear/tire combo??? We want this thing to go 12.0's not 13.0's...LOL!

In addition, the car is now 170 lbs heavier: Stereo, FULL 3" exhaust to the rear, and power windows...

A tank full of 91 octane and some octane booster and off we go to the track.

Three runs made. Never touched anything except for some Cal Track adjustments and ran a best of 11.77 @ 114.

I would post my "streetable" 340 combo but no one would believe it. So here are a few of the minor details.

I will keep it under 7K RPM, use 1.875 headers, a Strip Dominator and CE Slide-A-Links.

Static CR is a MEASURED 11.08 (may go a bit higher) and a custom cam.

Should fall into the 11's and my wife will drive it to the store.

Curious, what is the RPM at freeway cruise? Do I recall you're on 275/60/15's?? Thanks!

.030 trw replacement pistons,stock rods and crank.
555 solid flat tappet 258@50
iron W2s mild port flow 290cfm with indy intake
1 7/8header with 3"exh to axle
727 4800stall
4.88gears in 3250lb car 11.4s @118mph

Cudadoug are you saying that you change gearing to 3.91 and drag radial and went from 11.45 to 11.77 at 114. Thanks

3.91s were in place when it went 11.77. Changed the muffs to something quieter and changed to the 315/60 drag radials. The extra 600 rpm difference at the stripe appears to have produced the 11.45 vs.the previous 11.77. More speed too: 117 over the 114.

You know...This is a 4 year old thread you just I wouldn't hold my breath with that cuppa joe...