I got a 1997 4.3 liter fullsize truck. I want to put a 5.7 liter in it. what do i need to change?

first off you got to make sure the engine will fit in the
engine bay
then you will need make custom engine mounts
that will get you started

-Jesse-

DONT EVEN BOTHER. YOU HAVE TO CHANGE EVERYTHING. UNLESS YOU HAVE THE MONEY TO SPEND THOUSANDS OF DOLLARS. THE FLYWHEEL, THE TRANNY, AND MOTOR MOUNTS AND ETC. JUST GO GET 97 WITH 350 OR 98 WITH A 350. IN THE LONG RUN YOU WILL SAVE HASSLE AND MONEY.