Swapping same year Mercury powerhead from 150 EFI to a 200 EFI Questions

[11b330i]

So on the 93 150 EFI i picked up for 300$, the powerhead was junk. Found a powerhead from the same year for 900$ from a shop in town with the core of my old powerhead. Wondering if there is anything i should be conscious of for this swap (besides the obvious power increase). Will it bolt right up? Do i need any special parts? Thanks in advance

 

[wired247]

It will bolt right up. Ratio of the gear box isnt right for a 200 but that doesnt really matter. I run a 2:1 CLE and it works just fine.

 

[Dukedog]

Gear ratio should be tha same, Both 2.5's. Both 1.87's. Standard ratio's. Unless it's been changed. Tha 2 ta 1's were on tha 2.0 150 carb motors. Standard......... Some more stuff. XR6/MagIII were small case 1.78's for tha first coupla years then went ta 1.87 big case........Just another little tid bit for ya wired.