In big block Chevrolet factory blocks due to the common lifter mis alignment front to rear we handle it like this.If we install lifter bore sleeves to get them in the correct position we would warranty the cam and lifters,both parts and labor. without the lifter bores corrected we wouldn't cover the job. this is explained in detail and noted on the work order before the job is done so the customer can decide which way to go, that way if the cam fails there isn't any hard feelings.Bill