i had a 70 deville that got totaled but luckily i found a 66 deville drop top. the engine started knocking so i swapped out the engine and trans then junked the 70. i kept the 66s engine though im looking to have it rebuilt. but either way onto the issue. when i go to turn on the car i have to turn it on with the shifter between R and N for it to actually turn over. every other gear works properly R is reverse and D is drive same thing with N but for some reason i need to start it between R and N does anyone know what i need to do?