Can use the frame mounting locations on the firewall torque box? If so, I used a 4x4 cut to length and drilled to allow a longer bolt. I had to angle cut the ends to clear the contour of the firewall. Then I mounted the 4x4 across the firewall of the car. Jack stands or a jack can be used then and the sub frame is not an issue anymore. If you plan to replace any firewall section near the floor, this will not work.