use the search function. if i recall correctly, a few members have changed that item on their own and cost under 100 bucks.
write up on how to change the fuel sending unit.
How to Replace a Fuel Level Sending Unit D40
oh and a timing chain belt is an oxymoron. our trucks have timing chains and they are not, in automotive terms considered a belt. if you needed your timing chain replaced or rather the timing chain guides that are known to wear out, your truck would be making a "whining" noise.
good luck!