I like your thinking.
Use two DGV 32/36 Cortina carbs the total venturi area is 1.65 square inches rather than 2.05 square inches. Thats a 25% reduction. Cortinas overall average throttle area is 2.824 sq in, while the ADM 34 is 2.814 sq in. The Cortina produces a better signal to the jets than the two ADM 's on an unmodied 4.1 engine. I'm worried that the bigger ADM's will be too much on a stock six. If it is taken to the 200 hp level, the ADM's would be fine. In stock form the emmissionsAussie Cortinas had between 80 and 90 hp depending on transmission, while the Falcon had between 121 and 141, depending on the emission specs.
Using the Cortina 4 carbs, the minimum jet size is 115 for the secondary. The stock jets are 137 on the non emission types we used in Kiwiland. Make sure it has the bleed back tank return line so you can use the stock XE/XF fuel pump. use the stock Cortina 4 return line. I'd try it stock, monitor the fuel air ratio with a gas analyser.
I'd definately look at the propect of needing to reduce the jet sizes, as even the 80 hp ADR 27A emissions spec 2.0 cars from 76 to 82 were jetted richly. Emulsion tubes may need changing too.
That should be enough for a lot of power, 160 hp shouldn't be hard to get.
Some background info.
Basically, two ADM 34's are 280 cfm each at 1.5"Hg. Two of them is like one 4-bbl 550 cfm Holley mechanical secondary carb, and needs similar jetting for one of those on a 131 hp (98 kw) car. Since few people shove a 550 cfm carb on an engine looking for just the same performance, you need to look at two Cortina carbs. They are 227 cfm @ 1.5"Hg a piece, or like one 454 cfm mechanical secondary 4-bbl carb.
The stock 1983-1984 4.1 Falcon uses 98 kilowats of fuel from one carb. If you add as much fuel as the stock ignition advance, 256 degree cam and a great exhast system can handle, it will possibly give 116 kilowatts.
(The ADR 27A Falcons from 1982 to late 1982 had 105 kw, then there was a redution halfway through the XE model run to meet ADR 27B, and an undisclosed reduction for the for New South Wales Falcons as they had stricter emmissions than the rest of Australia, but most car makers standardised on one engine.)
New Zealand spec carby XF 4.1's with no emissions equipment got 103 kW.
When you double carb area without changing anything, you have to
1) reduce the primary and main jet sizes by 50%. There is a limit to how much you can reduce them, through. The maximum jet size in microns is the venturi diameter (both primary and secondary is 29 mm, in this case), divided by 16. That gives you a main or sectondary jet of 1.81 mm jet (181 microns) maximum. The minimum jet size is the venturi divded by 23, or 1.26 mm ( 126 microns). That's only a 34% reduction.
2) Check that the stock venturi diameter will work within the rev range. Remeber, the stock Falcon is a 34/34 throttle, 29/29 primary and secondary.
The stock 2-bbl 3.3 and 4.1's ran the same jetting and primary/secondary venturi sizes, just like the old 1.6 2-bbl OHC and 2.0 2-bbl Cortina OHC engines did. And the 4-bbl 4.9 and 5.8's. Ford used the idle adjustments to make allowances for tuning. All the smaller engines had a higher specific out-put, and the bigger engine had much better torque with little fuel consumption penalty.
The Cortina is 32/36, with a 25/27 primary and secondary. Its hard to fit the Cortina 4 carb to the X-flow unless you change the choke to a manual operation. Each Cortina carb could cope with between 88 and 102 hp each on a Cortina, so 176 to 204 hp could be had from two. My pick is to use it.
On a stock 4.1, the peak fuel flow area needs to be reduced by 50%, so if you have an ADM 34 with a stock set of main jets that are 145, then reduce to 125 at the very least. You'll find that the stock venturi sizes will suit a bigger XF EFI style cam at the very least, and the engine needs to be based around getting 220 hp with this.
My point is that the 4.1 is better served with a couple of Cortina 4 carbs if its stock, and a couple of ADM 34's if its worked to produce 200 hp or more. Bigger than XF efi cam, headers, better valve springs, better pistons etc.
