This got me curious, so I plugged the comp XE262 and the comp 280 cams into my Dynomation5 simulator (both installed at 106 cl), and it shows a 23 ft/lb peak torque difference. Here are the numbers the sim came up with:
Cam 262 280
280@100clRPM HP TQ HP TQ HP TQ
1000 75 391 68 359 72 378
1500 118 413 109 382 115 402
2000 161 422 148 387 155 408
2500 213 448 199 419 208 437
3000 260 455 243 425 252 442
3500 310 465* 293 440 308 462*
4000 343 451 337 442* 347 456
4500 359* 419 361* 421 368* 429
5000 350 368 359 377 365 383
5500 326 311 343 328 343 328
6000 286 251 311 272 303 266
The smaller cam really is a better fit for your combination. The larger cam is showing higher numbers for charge loss (reversion into the intake), this is one reason advancing the cam helps, the other is advancing the cam closes the intake sooner building more cylinder pressure.
After messing with this for awhile, I realized that your engine and setup is really close to stock, so I just plugged in the stock HP cam specs of 268/284 0.450/0.458, 115 lsa, installed at 106:
RPM HP TQ HPhr TQhr
1000 71 373 71 371
1500 114 399 115 403
2000 153 403 153 402
2500 207 434 207 436
3000 255 447 257 449
3500 306 459* 308 463*
4000 345 453 351 461
4500 367* 429 375* 437
5000 363 382 372 391
5500 341 325 348 332
6000 302 265 310 271
The second set of numbers is using the same stock 268/284 duration with 115 lsa, installed at 102 icl, but using the same (fast)lobe ramp rate as the XE cam, and 0.490/0.500" lift. If the Mr Six pack cam is simular, it might be the one to use?
