Replacing powerhead on 1997 8 HP Johnson J8SRLEUC 2 Stroke

[w2much]

I will probably need to replace the power head on this 8 HP 2 stroke engine. It is seized. Will the 6 HP of the same year work? Are there others which will match ?. What years are compatible?

 

[w2much]

I keep seeing 6 and 8 HP's mentioned as being the same. Need to purchase one that is compatable with this engine. Along with the above questions I am curious if the 6 HP and 8HP are similar to the 9.9 and the15 HP's in that the only real difference is the carb throat bore. I see 6 HP powerheads available but are all of my external parts from my 8HP going to work on a 6 HP powerhead?