Hello, first post here. I have a 1999 suburban 1500LT with 67,000 miles. The Sub is used to tow our boat around the Southeast. In an effort to firm up the shift characteristics and reduce slipping, I have found a electronic B&M shift plus controller (#70380) that simply ups the line pressure. The product is only listed for 1993-1998 Suburbans and Tahoes and 1993-98 pickups. As we all know the pickup line was changed over in 1999 to the newer body style and LS engine but the suburban and tahoe remained visually and mechanically the same for 1999. I contacted B&M and questioned whether this might in fact work on my 1999 suburban and they told me No, that the entire wiring harness and ECM is different. For the record, GM lists no changes aside from colors between 1998 and 1999. Can anyone confirm either position?