After finding a couple of problems with the Holley 3310 750cfm carb I have now. I have come to the conclusion that I should either rebuild it or buy a new carb. Here are the specs on my setup.
360, .040 over
KB pistons, final compression 10.5 to 1
Magnum heads, 2.02 valves, ported to the max
M1 dual plane intake
Holley 3310 750cfm vaccumn secondary's
1" carb spacer
MSD Ignition, 6AL, Blaster 2 coil, 8534 Dist.
Comp cams Magnum 280H, 1.6 rockers, total lift .512
Dynamax ceramic headers, 1 5/8 primaries to 2 1/2" X-pipe, flowmaster 40's
TCI 2800 stall convertor
Fresh 727, reverse manual valve body, B&M Megashifter
4:10's in 8 3/4
SS springs, 002/003
26" M/T Sportsman Pro's
American Racing Outlaw 1 wheels, 15x8 rear, 14x6 front
What would you do and why?
After running my 388 on the dyno last friday and finding the 750 mighty demon to be just a tad to small on the top end - I recommend you buying the same carb for yours, especially if you are considering stepping up a notch in cam size. I run a 254@50 555 lift. I believe yours is a 230@50. If you upped to the XE275 and the 750 carb you would probably pick up 40fwhp.
Let us know what you decide and how it works.
Too bad you are so far away - I have a 650dp speed demon on the shelf that would work great with your present setup as it is meant for a cam with duration like you have now.