Fun 340 head swap results

Long winded.
Took my stocker 69, 340 4spd dart swinger daily driver to our annual mopar day yesterday. I thought I would post my epic results. This thing has drove 16hr round trip and is my total driver. So, it’s not as fast as it should be for for drivability reasons cam, clutch combo etc etc. Have put 21k miles on it in 4yrs. Combo is a stock wore out bore, stock stroke, x heads that were only gasket matched. Has a crappy hydro comp street cam, Ld 340, 750dp. Works good to drive but wouldn’t rev like I want. Xe 275 comp cam, have tried everything under the sun to make it rev, 3 sets of valve spring combos, strip dominator etc and it was over it at 6k. Keep in mind I know what it wants for a cam but again, street car not my race car. Ran a 12.84@107.10 best after 3yrs of mopar nationals races and is fairly scienced out. This thing has factory non-hardened seats and are old, worn and need rebuilt. I decided instead of re-doing those, I would buy some new alum heads. I bought some eddy heads, I tubed the pushrod holes, then sent them to my buddy to port, still 2.02 valves, not a full tilt job... had another buddy help me fix the crap valve job. Went to the track yesterday and ripped off a 12.23@111.69, I expected half that gain and to say I was elated is an understatement, it revs up now too. I thought I would share my finding. Not touching a screw besides the heads and picking up that much. Not very often a person goes to the ticket booth and is rewarded with that kind of gain from my experience.

Great results! I'd be excited too.

Excellent results! Definitely a performer.

That's gotta be very satisfying !

Very nice! Now if we can just talk you into replacing that 340 crank with a 4 inch stroke model.......

Did you have to use offset rockers?

Very cool, i had a mid 11 second isky solid W2 69 340 dart 4 speed back in the late 70's early 80's, They are fun cars

That cam is very similar to the 231/239 @.050 Ultradyne Hydraulic Flat Tappet cam that makes for a really strong 340/383 replacement cam with bolt ons, It really picks up the power without killing anything off the bottom.

I suspsect with 1.6 rockers you'd make a bit more power if you have the spring clearance.

Very nice gain. Now it can breathe.

How much does it weigh?

Trust me I know, I have race car stuff and have went mid to low 9s since 06ish with w2- W5- Indy stuff. It’s hard for me to refrain but this deal is 100 percent a stock grandma og 1969 dart swinger 340 car. I’m trying to keep it 100 percent driver. Struggles lol. The 4in crank stuff is key.

I do not but I’m tempted to do so after this.

Thanks, whatever a bone stock 69 340 swinger weighs with a scattershield and cragars. Seems like I weighed it on my scales and was close to 3375 comes to mind.

Outstanding gain, and I like that you're really driving the car long distances.

Thanks, it’s what the wife and I love to do now. Cruise the street car. It’s so fun.

It's tough to do a car and not get carried away.

My neighbor has a '70 Chevelle and I have the '63 330 and we drive all over, cruise, go out of town, drive it to work, etc.

I've put close to 8k miles on my car in the last few years, lots of dragstrip passes and love every minute of it! His runs low 11's and mine runs low 10's.

What gear is in that car?

Are you anywhere near redline in the traps and I'm guessing by the speed your at least a few 100 more rpm at each shift point and through the traps.

I used to turn my W2 like 7600 and above 4000 it felt like a nitrous shot, I imagine you benefit from jetting-up a bit for the new heads, unless maybe it was a little rich to start with on the big end and now it's just right.

I put 4.88s in it when I go to the track, it wouldn’t get out of its own way with the old heads hence the gear to make it go. I think it would like 56s now with the new heads. Crosses at 65+ now. The cam isn’t all that happy there unfortunately. I had w2s on a stock bottom end 340 in the mid to late 90s. Had a .557 cam, it liked 7k best. Went 11.17@118. Way back.... was fun back then. That’s what this car is to me too. All fun

Agreed, I have my high school car, another original 69, 340 swinger that has a w8 headed, f2 procharger on Holley dominator efi and air to water that sits in the garage and I take my street car 4spd to the track lol.

Yeah I figured you had to have some gear in it!

I ran 4.56's back in the day but 4.30's hooked a little more consistently on the street, had to slip the clutch to get it to bite and then nail it. 56's used to break loose in second if I shifted too fast.

I carried 2 40 pound bags of sand in the spare tire well!

Nice job Ryan! Super cool driver. Impressive results.

Thanks, now to try diff intakes and see if I can make it go 11s. I have a nice strip dominator I converted to square bore to try and a air gap. Maybe a better header as it has the cheap competition hookers on it. I have gained a lot by trying diff headers on my other car on previous mild combos.

Sounds like the results were well worth the work. With a bit more tuning, bet you can shave that time down a bit more.

I’m positive of this, if I would go more than one time a yr that would help too lol. In regards to whittling down the et.

Out of curiosity, since this is a driver, what kind of MPG do you get?
Head change make any difference on that?

Love that you drive it

It got 14-15 on a drive like an hr and a half long on average. I am unsure now as I have only put about 50miles on it since the swap. I will be finding out tho.