I just started to occasionnally race my 99 5.4 regular cab f-150. So far I have raced a chevy 1500 a 98 model with a v8. Won that quite easily. A 2004 dodge dakota with a 3.7v6. I won that with a 1 1/2 car lengths margin. Just yesterday I raced an 01 nissan pathfinder and a 2003 mazda 626 with a v6. The pathfinder beat me by a car length but I was catching him, and the mazda ate my dust. Mind yall that all these other vehicles have less than 60,000 miles and Im about a week away from reaching 145,000 miles. The only problems Ive ever had have been an idle speed motor and windshields cracking due to stress. Anyways I was wondering if anybody could tell me what to look for in the way of problems that could arise. Once my engine finally decides to go Im going to put in a 4 valve 5.4 navigator engine then supercharge it. I know a descent amount about cars but some feedback would be great. Im hoping to at least put on another 100,000 miles on it. Also everyone talks about getting 15 on the highway with a 5.4, but going 65 Im getting 19 on average. City driving Im getting 15.

 

Regular cab 2WD? Is your truck a manual? Bedcover, tailgate up/down? How do you get that mileage?

 

i get about 10 on the interstate.but i have a slightly heavy foot. i'd say a new 5.4 3 valve out of a truck would be the best swap. they've got more power than the nav motor anyway. atleast the older navigators anyway they mighta beffed em up a little.plus it'd be an easier sway and you could use the new 4r 75 tranny, which from what i saw when i drove the 04 f150 its a good solid tranny

 

Its a 2wd automatic with 3.55 gears. Going 65 on the highway with an light foot on the accelerator. I rack up those kind of miles by driving From Dallas to San Antonio a few times a week. Used full synthetic oil and drove with tailgate down. About the Navigator enigine why did they make a 4 valve and a 3valve 5.4? The only difference is the 4 valve have slightly less torque than the 3 valve.

 

i've wondered about that myself.they coulda saved money on r&d by just freshening up the 4 valve and drop it in the f-150 but i know that 3 valve will flat out run.i'm thinkin of swappin to one whenever mine lays down on me,which from the looks of it will be a long time from now