Since I've pulled my engine on my 37 and wound up doing alot more than what I expected I found my self with no room to mount my master cylinder except under the floor board.Do I need a residual check valve now since gravity is not going to be working for me. Also how far should I mount it from the master cylinder? Since I have disc on the front and drums on the back do I need to mount two and if so what size(pound) should I buy?