Is this for your 87 truck? If so then it will provide a slight improvement over your stock booster which has a smaller diaphragm. Without changing the master cylinder, the difference would be that it will require less pressure on the pedal to achieve the same amount of force at the brake pads.
The reason I have the booster in the first place is because I am using an FJ80 master cylinder with my 1st gen 1981 booster. So I put a larger master cylinder on and did not change to a larger booster to compensate. This gave me great stopping power but at the cost of more force required to hit the brakes. I bought the 3rd gen style booster to upgrade, but found that on a 1st gen Hilux, the booster is so large that it hits my steering shaft! This should not be a problem on your 2nd gen.
If, for any reason it does not fit your cab, I am happy if you want to return it for a full refund
If it feels too touchy, then get a larger master cylinder, like a 3rd gen or a FJ80 one. Then you'll have the best of both words!
BigMike
