How the 6802 MPU board differs from the -35 board
The 6802 board runs a 6802 CPU instead of a 6800, a 5114 RAM (1024x4, same 18-pin footprint) instead of a 5101, and needs no 6810 RAM. It can take one 2764 EPROM at U7 in place of two 2732s at U2/U6, uses a 2 MHz crystal instead of the clock circuit, has a new reset circuit (74HC538 plus 2N3904/2N4401 transistors) and extra jumpers W1-W6 near TP5. Its software matches the -35 board.
Systems
Source: Repairing Bally 6803 Pinball Games from 1985 to 1989, Clay Harrell (pinrepair.com)