[&:] Hi I've got a 96 with 3.8L V6 engine and Swapping it out for 99 3.8L V6 engine. The problem I have is the 96 has two fuel lines comming to the fuel rack and the 99 only has one. Anyone know what I should do about this? I'm sure one is a return line, should I just block it off or will that mess up something?

 

find the return line and block it.

99 has a returnless fuel system. so, you must use 99 engine, 99 computer, and perhaps 99 fuel pump (not sure about the fuel pump).

Try blocking the return line, install engine and computer, and run it. if it works, fine. if it doesn't you have to modify your fuel system at the fuel pump. if you don't have 99 computer or if that doesn't work, transfer either the fuel rail off 96 or the entire intake manifold with everything on it.

 

...and as long as you gonna transfer the manifold, or if you have the engine out. clean the entire manifold, egr, and everything. port match the manifold, and flow match the injectors.

 

On a 3.8 v6????Why???

 

Hmm missing the point of an engine swap are we. Get a 5.0 or 4.6

 

why not, the 99 3.8 is just as powerful as the tired old 4.6 npi romeo. you can also do it for mpg reasons. i don't know about you all, but even if i had a lawn mover, i'd probaby modify it.