if you want to create a dual drive cambelt gearbox you will probably neen the below from MFA Como:-
Bearing Blocks
Part No. 919D30 5mm I.D.
(19.06 x 19.0mm x 10mm) 32g
Part No. 919D30/1 6mm I.D.
(20 x 20mm x 12.5mm) 32g
Part No. 919D30/2 8mm I.D.
(19.0 x 19.0mm x 13.0mm) 32g
Part No. 918D10.
Bearing Blocks. 4mm I.D.
(20 x 20 x 12.5mm) . 32g, extra pulleys and longer belts