its a midwest aerostar 60 its old, the date on the instructions is 1987. from what i understand, its still made, and i got it for a really good price, so i got it. it looks straight, but i put a screwdriver between the back of the engine, and the back of the mount, to make sure i could get fuel line through there as per the instructions, and i noticed the gap difference. like i said before, the engine fits very tight in the mount, so there is no right/left movement,  but you can slide the engine barely from the front to back of the mount. thanks for taking the time to read this and give me some help with this. i need to make sure this is right so i can learn to fly with the least amount of problems.