Little question
 

Hey I just got a 1990 F150 XLT Lariat 5.0L and I was wondering how hard or easy it would be to convert it into an old Lightning, that or what type of performance parts are needed to make 5.0L go a little faster. Thanks.

To build a Lightning clone takes a different engine, different tranny, different suspension, some chassis stiffening, different wheels and tires, different guts in the rear axle, some differences in the brake system, different gauges, different seats, all it takes is money....and lots of it.

To build up the 5.0 to make it "a little faster" is easier. A set of GT-40 3-line or GT-40P heads with appropriate headers, an Edelbrock intake and T/B, a Crane 2020 or 2030 cam and roller rockers, a set of 4.10 gears and a limited slip with some suspension and brake upgrades should do the job...and still tear a hole in your wallet.