GM 120 replace with GM 140

[bobwinkel]

Will a 3.0 will directly replace a 2.5. That is, it will bolt in and fit the out drive etc. I have a 3.0 long block and bad 2.5. I have heard there will be problems putting the 3.0 in place of the 2.5 unless you swap everything "from the pulley to the prop nut". Any advice you can offer will be appreciated.

 

[Howard Sterndrive]

not sure why a mod moved this thread here - it was in Mercruiser - maybe give some year and model info of what you have and what the donor is and request a move back to Mercruiser if that's what you're working with.

If the 3.0 is pre-1990, it should be the easiest swap in the world - all externals are the same dimensionally. The only thing that can get weird is exhaust manifolds between dissimilar heads, but most of that is again, after 1990.