305 crank in a 350 block what is it and will it fit?

it should de-stroke it to something around a 327. it will fit but be sure to check for crank to piston and piston to head cylinder top clearance to ensure you don't run into engine detonation.

ummm no 305 and 350 have same stroke a 400 crank would make it a 334... same main and rod journals also stroke is 3.48