I went the 98 LS1 4L60E from TA with 24K on it.
back in 07 for $5K. The extra expense came after with Street & Performance pass. side alt & AC condenser tuck in unit. $2K, then $250. for fuel rails, $200. for air intake, $550. for Harness/Computer revamp, $130. engine mounts, lots of work rewelding exhaust for Cats,$850 for LS1 Walker rad and a few other items. Probably about $8500. cheers