lower unit swap from 1974 850 to a 1981 80 horse

[koma80]

My son is swapping out his lower unit on his 74 model 85 horse merc with a 81 model 80 horse merc my question is 85 has a thrust button on the driveshaft and 80 doesn`t is there going to be an issue with out it?I`m getting old and have the sometimers at times

 

[Kitimat_DoubleEagle]

I just installed a lower unit from a "newer" 80hp motor with out preload pin onto my 1975 850 85hp motor that originally had the preload pin. No issues bolts right up

 

[Kitimat_DoubleEagle]

I just installed a lower unit from a "newer" 80hp motor with out preload pin onto my 1975 850 85hp motor that originally had the preload pin. No issues bolts right up