Bruce Lang is running a 470 in his 68 NSS barracuda with the TF270s and a Modman with 1 1/2 spacer best of 9.48 @ 3200 lbs.
I just can't seem to get my combination to work that well.
Primarily was wondering if I needed to go with more duration on my cam, like 280

What cam is in the Barracuda ?

9.50 should be in the 140mph neighborhood.
At 3200lbs....... I’d be thinking it would dyno at 750-770-ish.

124mph @ 3800 should only take about 610-620 on the dyno.

whwhatat about monoleaf and caltracs. that would drop about 40 pounds. what tires you run.

What cam is in the Barracuda ?

9.50 should be in the 140mph neighborhood.
At 3200lbs....... I’d be thinking it would dyno at 750-770-ish.

124mph @ 3800 should only take about 610-620 on the dyno.

I have used a smaller Comp Cams solid roller cam than yours in my old pump gas Duster that weighed right at 3450 Lbs. with me in it, that car ran a best of 9.993 at 134.6 MPH through the 3.0 inch full exhaust system to the rear bumpers on Oregon pump swill. It would run mid 1.40 in the 60 ft. with a older T/A SS 8.0 inch race hemi converter in the car.
It was a ladder bar car with coil overs rear suspension, 15.0 inch extended Strange double adjustable rear shocks with a set of Koni SPA front shocks on 315x60x15 M/T Et Street Radials back in the late 2000s and early 2010/2011
That cam had 260@.050 with .420 lobe lift on the intakes and 266@.050 with .409 lobe lift ground on a 108 LSA installed 1 to 2 degrees advanced on the intake lobes with a set of Harland Sharp 1.65 ratio rockers that netted right at.700 lift at the retainers with light weight checking springs with the lash set .006 tighter for the aluminum heads at room temps.
That motor was a 400 block bored to 4.375 with a 4.300 stroke Ohio Crankshaft custom ground stroker forged steel crank for street use, not a lightweight all out race only crankshaft That car and motor made me very happy, it exceeded my wildest wishes
You have room for plenty of improvements on your deal, now comes the hard part and where to start I would work on the chassis before trying to make more HP and torque
My reasoning is it not hooking well now with the HP you have so adding more won't help it hook, it should do just the opposite

Joe went 140 @3220 in my old car on super stock springs. 9.66
Motor made 708 on Best Machine dyno
775 horsepower should run WAY better than 140 in a 3200 pound car.

... it’s unlikely you’ll find a bunch of improvement without finding more HP.

From what I’ve seen, the “typical” bracket car usually shows around a 10% lower HP number than the STP power from the dyno.
140@3220 shows 680hp...... which is only 4% off the 708hp dyno number.
Obviously, some cars are better than others(even in the middle of summer my friends stocker shows it makes more HP than it actually does).

140@3200 shows 675hp.

So, 750hp on the dyno.....-10%.....675hp uncorrected as the car is sitting on the starting line.

I usually shoot for 10% over what would theoretically be needed for a given MPH/weight.
If the car ends up being better than a 10% package and goes quicker.......let’s just say....... I haven’t heard any complaints when that happens.

In no way is this derogatory. I think something is missing in the current combo. You should be quicker now. I do not believe it is in the intake or carburetors. I am running the same combo.

Our NSS wagon has been 10.80s ( i do not remember the exact et )
It is a 30 over 440 with 10 to 1 comp, SR heads, indy dual plane intake, single edelbrock 750, 4.56 gears in a dana, caltracs, also a good converter, at 3775lbs

My old NSS combo went 9.80
It was a 493 or 496 ( i dont remember ) with SR heads, 12 to 1 comp, modman, a pair of edelbrock 750s, an older indy/comp flat tappet cam in the range of 607/614, with 4.10 gears in a dana, after several tries we found a very good ATI converter combo which is where a most of the ET came from. This is in a ladderbar car at 3600lbs

My this year NSS combo has been 9.49. I do not turn this motor hard. I have no doubt there is more in it.
It is an aluminum block 540 with -1 heads, also 12.1 comp, modman with Your upgrades, has had edelbrock 750s and 800s on it, comp 682/682 roller with 284/288, with 4.10 gears and so on. The car is lighter with the aluminum block.

That car was on super stock springs, cheap 3 way CE shocks. Nothing trick for sure. Maybe its just more the fact the dyno was more real world than others

That’s tested on the same dyno where the typical result is usually a car that is showing close to a 10% loss.