A Northeast Washington used car dealer was found guilty yesterday by a D.C. Superior Court jury of conspiracy, grand larceny and receiving stolen property in connection with a major auto theft operation.

The jury, which deliberated five days, convicted James McRay, 44, of 10325 Geranium Ave., Adelphi, on 17 of 31 counts in an indictment that included charges of grand larceny, conspiracy and unauthorized use of a vehicle.

Judge Robert A. Shuker declared a mistrial in the cases of Willie Henry and Robert Ware, two locksmiths who were also charged with conspiring to steal cars and sell their parts, after the jury dead-locked with a vote of 11 to convict and one to acquit the two men.

The government contended in the lengthy trial that McRay, Henry and Ware conspired between 1971 and mid-1978 to steal vehicles -- including cars, vans and tow trucks -- and to remove and sell their parts.

Key witness in the government's case was Andre L. Holley, 25, who testified that he stole cars on order, depending on what parts McRay needed. Holley said Ware and Henry made the keys he used to steal as many as 12 cars a week.

On the witness stand, McRay, a native of Wilson, N.C., denied participating in the elaborate scheme.

But in exhaustive testimony, Holley described how he was called upon by McRay almost daily to steal cars for parts to refurbish autos on McRay's used car losts at 2101 Benning Rd. NE., and 1027 Bladensburg Rd. NE.

After receiving an order for a specific car from McRay, Holley said he would cruise the Maryland and Virginia suburbs in search of a likely prospect.

Holley agreed to testify against McRay, Henry and Ware, as part of a plea bargain with the U.S. attorney. The government agreed to drop 75 of 77 charges against Holley for unautohrized use of a vehicle in exchange for his testimony.