1974 360 horsepower rating

I've been doing research on the 1974 duster / dart sport with the 360. From what I've read the 360 in 1974 was rated at 245 horsepower at 4,400 rpm's, is this over rated or under rated or accurate? The reason for this is I've been looking at a 1974 duster with the possibly of rebuilding the 360 for pure stock muscle car drag racing. The engine has to be correct for the year / horsepower claimed, heads can not be ported, gasket matched, stock size valve's have to be run. I haven't been able to find out if a comp valve job is allowed but I doubt it. Compression ratio can be 1.5 points over stock and I have found two different ratios for the '74 360, 8.4:1 and 8.7:1. Cam has to have the stock lift and duration. Factory exhaust manifolds. Curve kit is allowed as is a high performance coil as long as it is the same shape and color as the original and has to be mounted in the factory location. What horsepower would be possible with only a increase in the compression ratio and somebody who has great tuning skills? Thanks everyone for any help and advice.
I ran almost exactly that engine in a 1970 Dart, a .040 over 360 out of a 1975 Dart Sport, stock heads and stroke, stock electronic ignition, backed by a 727 and 3.23 geared 8.75 rear with a Tru Trac differential, only changes were an Air Gap intake and 750 cfm Performer carb, TTi headers, and welded in subframe connectors. Car would run 13.80s all day long on drag radials, 14.0 on Cooper Cobra street tires, through 3 inch exhaust. I expect it could have been a little quicker with a well built 904 transmission. Car was 100% steel, with a full bucket and console interior, rear seat, spare and jack bolted in place, and usually 3/4 of a tank of fuel.
That class sounds like it would be a lot of fun to run in.