I believe the XE274H (230/236 @ .050) should outperform both of those cams. 2.5" exhaust should be fine. Usually 3" exhaust if your over 500-600hp. That 288H Crane Cams is only 226/230 @ .050 with a 2,500-5,500 operating range. The 280H Comp Cams is 230/230 @ .050 and 2,000-6000 operating range. The XE274H has an operating range of 2000-6000rpms.

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347 Stroker/XE284H(284/296 dur, 240/246 dur @ .050), BG 650 VS Speed Demon, Ported Victor Jr intake, Jack Roush World Product (ported from 180cc to 195cc) Jr Heads(upgraded to 2.02/1.60 valves) 260cfm/190cfm @ .550 lift, 11:1 comp... 450-475HP