I don't know who Magic Racing gets there big bore kits from. But as far as I can see there good, and have yet to heard of one that cracked from them. There prices are always pretty good too. Oh ya and there in Michigan. The kit with all the trimmings (cam,o/s valves, hardened rockers ect.) cost under 1300$. If you have them do all your work I think its about an extra 150$.
440, Ross 11.5:1 piston, Web cam 479 grind, race port & polish, oversized valves, hardened rockers, CRF450 cam chain, 39mm FCR carb, lightened Flywheel, Stock clutch, WB CDI box, K&N filter , WhiteBrothers E-Series full exhaust, Sidewinder Chain, 15/36 gearing, open airbox, LSR Axcaliber +3.5 axle, Houser Racing +2 a-arms, Elka triple rate, fully adjustable front shocks, +1.25 Houser swingarm, Tag Metals X5 bars, Arens +1 steering stem, Muscle steering dampener, Stainless Steel brakelines, HeatSeeker temp. guage, Pro Design kill switch, DG Pro Series nerfs, 8 run Hauler paddles. ~~http://www.sounddomain.com/id/trick440ex~~