I have a 02 1500 with the 5.9 and was wondering is it easy to drop in the 5.7 hemi or do you need to replace everything? I know the 5.7 has allot more hp but it gets bet mpg than my 5.9 too. It sucks Im getting 9.5-10.4 mpg according to the overhead computer

 

Sucks..that was the reason I traded my 5.9 in.. Gas Milage sucks on them.... and the hemi is puts out 100 more horse and get's better MPG ... I say do the swap!!...

 

It ain't like the good ol days.
To do an engine swap now is big big work.
I am pretty sure the trans. will bolt up....but
The 5.7L has an electric throttle, 5.9 has cabled throttle - so that will have to be changed.
ALL your Control Modules will have to be changed.
Your looking at a lot of money...you would be far ahead to trade.

 

but, to have a 2002 with a hemi, now thats special

 

Best bet is to find a 2003 hemi that somebody is parting out or is wrecked in the back or something. That should net you all the electronics, etc. Good luck!

 

The HEMI is a pretty Hi-tech motor. I would think it would be a nightmare.

 

Screw it I have decide to go with 4.56 gears, full exhaust and get some 35" tires instead of my massive 37's. The 5.9 enging is a good engine and it has low mileage on it still so hopefully Ill get some inprovement with those mods.

 

Your other option of course is to stroke it out and either hog your heads out some or throw some aftermarkets...a 400 cube or so small block is an awesome thing....