I'll be upgrading to a BG HR220 fuel pump soon and am considering swapping out the 800 Qjet for a Demon 1000cfm unit at the same time. Are there altitude concerns other than jetting? As in, vacuum being too low and such? Too much carb? I wanna get snotty but don't want to spend $$$ where unnecessary. The combo is (future additions in parentatsis): .038 455 11:1 Ross - zero deck B4B dual pattern 800 Qjet (1000cfm Demon downleg) Stage 1 fuel pump (BG HR220) Iron Stage 1 heads - 260/190cfm 224/236 494/506 cam (TA "Street Dominatior" cam: 238/248 - 520 @.50) Stock rocker assembly (TA 1.6 or 1.65 Roller Rockers) TA 1-7/8" headers w/2.5" Flowmaster & 3-chamber (will add 'X') Stock rods polished/shot peened w/ARP bolts. Oil mods done. Pan baffled. VP400 w/1600/3200 stall 3.55 posi (3.89 Ford 9") Hotchkis upper control arms, air bag, boxed lowers. Best et with current combo. 4000lbs. w/driver: 13.01 @ 4500' altitude. No 60' times or trap speed (back woods track). Critique the whole combo if you'd like. Tell me where you'd make upgrades. (I know about the heads... someday Stage 2 aluminum). Thanks.