I posted wrong model number on my last post. Sorry about that. I have a 1978 Evinrude 6hp. Model 6805 B. I had posted it as M, not B. I have a long shaft motor. I bought 2 used motors just like it for parts. I would like to change the lower unit from long to short lower unit. The 2 that I bought are short shaft type. Someone that I was speaking to about this, told me that I will have to remove the power head. As he is not a regular boat motor mech., does any one on here know if I have to remove the power head to change from long to short lower unit? Thank you.