From listening to people and hands on experience mags should be checked yearly but I have had a internal vertex mag for years and it's still kickin (beleive me I know it shocked the @#$% out of me just a couple a weeks ago when I loned it a friend). I have went to the MSD mag now and I love it. I will always send my mag stuff to a mag shop but I always check my injectors myself as the post before stated there is not much to wear out (bushings, linkage, heims, ect.) If you have any other questions you can contact me through a PM or call 812-606-6687. I might not be able to answer your question but I can try to find someone who can.

Nick Johnson
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