Coconspirator hearsay is admissible under Federal Rule of Evidence 801(d)(2) (E), if government makes a 'sufficient showing, by independent evidence, of a conspiracy' as required by United States v. James, 590 F.2d 575, 580-81 (5th Cir.) (en banc), cert. denied, 442 U.S. 917, 99 S. Ct. 2836, 61 L. Ed. 2d 283 (1979). The government need not prove a conspiracy by a preponderance of the evidence in order to admit coconspirator hearsay statements, but need only introduce 'substantial, independent evidence of a conspiracy at least enough to take the question to the jury.' James, supra, at 581, quoting United States v. Nixon, 418 U.S. 683, 701, 94 S. Ct. 3090, 3104, 41 L. Ed. 2d 1039 (1974). However, United States v. Nixon, 418 U.S. 683 was decided before Congress enacted the Federal Rules of Evidence, and Rule 104(a) provides that, in determining preliminary questions concerning admissibility, the court 'is not bound by the rules of evidence' (except those with respect to privileges), thus authorizing consideration of hearsay. Such construction of Rule 104(a) does not fundamentally change the nature of the co-conspirator exception to the hearsay rule. A court, in making a preliminary factual determination under ...