Have been working on a '75 Plymouth duster with a transplanted '77 400 B engine big block, 727 auto, and 3.23 geared 8.75" 742 case axle.
When I started, the engine was stock (rated at 190 hp) with the only deviations being a switch to a holley 4160 600 cfm carb and an electronic ignition conversion replacing the lean burn crap. 452 heads, tiny stock cam and 8.2:1 compression, also.
I built the engine last summer: .030 bore job for a total of ~405 cubic inches, Kieth Black 9.0:1 hypereutectic pistons, stock crank and rods- all resized with new bearings, rebuilt 452 heads, summit racing hydraulic flat tappet cam w/ 282/292 advertised duration and .465"/.488" valve lift and advanced 2 camshaft degrees/ 4 crank degrees, rebuilt Holley 3310 750 cfm vacuum secondary dual feed carb w/ #72 jets and Quick Fuel Technology adjustable billet secondary diaphragm housing and .037" accelerator pump discharge nozzle, Mopar Performance electronic ignition distributor with one stock advance spring and one Mr. Gasket light weight advance spring ( I found that with both lightweight springs, the idle was very unstable; ok for a race car, wouldn't recommend it on a street car), summit aluminum radiator, and also added a cheetah full manual valve body to the 727 and a B&M Star Shifter and trans cooler. Total timing is set at 36 degrees before top dead center with full mechanical advance at ~2400 rpm. The intake and exhaust manifolds are stock (for now).
This combo cost me a little under $2500.00 to put together not including what a block and heads would cost (they came with the car).
I want to run it at Knoll gas motorsports park in Martin, MI when it is fully broken in. As of right now I don't have any numbers to back it up, but I can say that I had the secondaries on the carb disconnected during the first test drive so they did not open at all, and it is far faster on just the primaries now than it was on all four barrels before the build. Hooked up the secondaries and did a burnout in front of the house and it literally dug ruts in the asphalt. It has more low end torque than the 255/60 R15s can put to the ground, pulls hard all the way to redline and barks the tires on the 1-2 upshift.
From a purely subjective point of view, it feels quicker than my uncle's stock '71 Trans Am 455 H.O.
I will let you guys know what happens when I get it dyno'd and when I finally get it to the track.