hi everyone . the front of my boat sits about 6 inches higher at the front of the boat than the back of the boat sitting on the trailor . i want it to sit level on the trailor . i have ajusted the front rollers down and the middle rollers down but the bow is still sitting higher than the back of the boat . can i put a block of wood under the transom of my boat in the middle right at the very back and jack the back of the boat up and adjust the back rollers up ? or is this to much strain on the back of the boat ? the trailor is a calkins . thankyou .