You have already won half the battle if the engine is complete with accessories, harness, computer etc.....
I say do it..
It will weigh about 225 more lbs or so than a stock 5.0, so if it were me {especially since tha indipendent rear from a cobra sucks for drag racing, I would put a built 9 inch rear out back to offset the added weight up front..
{a stock k member from a 96 4.6 gt will work by the way, so no need for high dollar stuff there, you will just need a BIG cowl hood, or no hood at all for a while until you source funds..
You also need a good tranny...
Now what would be HELLA COOL, would be a Navi Engine AND Tranny swap {yeah, you would have to cut some floor pan, but thay have a hell of a tranny in them {same as in the lightning}...
There was a stock navi runnin 15.20 at the strip here in ga a couple years back.
Now imagine,
7500 lbs SUV + navi = 15.20 or so..
3500 lbs CAR + navi = 11.20 or so..
I mean, I know tha 351 swap would be a "quicker fix"
But ANYONE can have/do that....{nothin against anyone here who has by the way}
Hell, I would throw in a set of flat top pistons while I was at it {about 650.00 a set} and up the ante another 50h.p. or so...
But just dont let the 5.4 DOHC design scare you, once your in there, its just an engine, 2 of everything with 2 chains.. Just dont put your cams on backwards if you swap them {I did on one of my buildups in the early years}
Just thinking out loud here..
L.
{wish I had a friend who had a junkyard!}