How different are S and W M and P frames

[fightinghamster]

So I have a first generation smith and Wesson m&p 40 and I’m looking at a CAA carbines conversion kit for a smith and Wesson M&P 2.0, will it fit my first gen frame? Are the guns that different? Any information is appreciated

 

[edgy]

If I remember correctly, the Gen1 will not fit a Gen2 CAA kit without modifying the frame. My bud who is a big M&P guy has done it, not sure but you may be able to find something on YouTube to guide you.