Want this question answered?
Yes.
No
yes it will and its about the best thing you could do to a 240Sx.
Yes
If it is the same engine (the I4 or V6)
Yes it will fit in but it will not bolt up to transmission
YES
Yes a rb20det will fit
no
Will a 1998 3.8 mustang engine fit in a 2000 Mustang 3.8 engine?
yes it can.
Will a 304 engine fit in a 1998 TJ jeep wrangler?