The only thing you have to do it to tune your model. Check is engine aligmnent, you simply have to add "shims" (is that the correct word?) to add upthrust or side thrust, the firewall is already having a angle to fight the torque of the engine , but you might have to add more !!!!
Just add small washers to add space behind the firewall and the engine mount. This should correct the problem.

My funtana is having the same problem, it would simply not stay in position and slide to the right side of the fuse, so I had to add 3/4 rudder to the left to compensate and even I could not keep it straight vertical to ground, I just added a few thin washers behind the the engine mount and firewall to decrease the angle of the engine to the right and it helped greatly, I am not still finished, it takes many flights to properly tune the side thrust ratio and up/down thrust ratio.


By the way the 14/4W makes the job, but I am affraid the 70 is a litlle underpowered. I have a Saito .91, Wow. !!!!