I've been blessed with a totally stock 1982 B-code Mustang, has optional 3.3L 87hp 6-cyl with its 1-bbl Holley carb,
That's the sky blue high mount starter engine 3.3, Bordeaux C3 auto, 2.79 gears, small TRX P190/65 390 tire package. It's still LHD, and quite unlike the United Kingdom RHD conversions which had TUV/Type Aprroval Capri 2800 tail lights and reversed firewall, but it does have the specially cast pods for British/German spec Ford Granada MkII fold back mirrors and the metric speedo.
It's a 1983 rego year Japanese market export, Canadian full metric speedo with 57300 kilometers (35 590 original miles), stock California emission spec, heavy duty battery, tilt wheel, intermediate wipe, A/C.P/S
Others with the C4 are mostly low mount,
Mine is high mount starter
Its magic on the road, has a peachy smooooth engine which mates gracefully with the smoooth French transmission. Its got a great ride and suspension and steering and brakes and general feel of the car are light years ahead of the 1982 Falcon. Performance is slow as the 1982 B code lost 7 hp over the 1981 versions but it keeps up with modern traffic. Same year Aussie Falcon 3.3 had 120 hp and weighed in at about 2919, not 2622 pounds. It did 18.5 seconds as a 3speed auto and 17.9 seconds as a 5-speed manual for 111 mph, but my Mustang auto takes about 20 seconds. The rare Californian spec RS Capri 3.3-speed SROD with 3.08 diff (2.49 overall diff ratio with 0.81 overdrive ) and 97.5 hp 2-bbl Holley Weber took 19 seconds to cross the 1/4 mile, and couldn't break 90 mph!
As for fitting a 250 engine, the Aussie block is smaller, and about 1.5"narrower than the US 250. Here is a copy from Jack Collins whos mates fitted up a triple carb, dual header US 250 to a Fox Mustang