Upgrade plug and play sound for Lionel 18000 PRR B6

The original K-Line B6 had RS4. The chips out of the RS4 boards will fit and work nicely in the RS2.5 boards.   If you could find one.  I have upgraded an 18000 to TMCC using an ERR AC Commander in the loco body and a RS 2.5 board in the tender. I used a Lionel Camelback sound set in the RS2.5 board.  It sounds close enough. It also has a MTH fan smoke unit, four chuff sound and smoke and coil couplers in each end. One must also take into consideration that the original Lionel 18000 B6 was a model of the first B6 which is a different smaller loco than the B6sb which is what all the 3 rail B6'es afterwards were models of.  You can see it's tight in the tender and the loco.  The cross-brace which holds the plastic coal pile had to be removed so I glued the coal pile in place. I also changed the 2:1 upper gearbox to 3:1 changing the final drive from 14:1 to 21:1. Note the brass gear box cover against the front side of the motor mount to keep my soupy gear lube contained.                                                                 j