i have a 71 convt with a 351c 2v i need to replace the rocker arms and dont have a lot of money to spend right now however i have looked in the magazines and they all sell the rocker arms for the 351c, m and 400 as one i have an extra 351m sitting in the garage that my brother no longer wants would i be able to swap the rocker arms and use those with out having to buy new ones