Mazda RX-8 Workshop Manual page 2216

Bolt length
A: 55 mm {2.2 in}
B: 70 mm {2.8 in}
Tightening torque
37—52 N·m {3.8—5.3 kgf·m, 28—38 ft·lbf}
Power Plant Frame Installation Note
1. Support the transmission and differential so that they are level using a transmission jack.
2. Install the power plant frame.
3. Install the plate.
4. Temporarily tighten the bolts and nuts as shown in the figure.
5. Tighten the nut B until the power plant frame is seated in the differential.
6. Install the heat insulator, exhaust manifold stay, catalytic converter, middle pipe, main silencer and front tunnel member.