94 Ford ranger power problems

[ncsdaonex]

So ive been driving my 94 ford ranger ext cab, 4x4, 5 speed, 4.0l, for about 4 months now. The truck was totaled a year ago when I got it, I pulled the entire truck apart, new frame and new front end and swapped it from auto to manual, heres a list of the only parts not installed in the truck - tranny wiring harness (theres a wire ran for reverse light and 4x4 low range so everything works), the fender liners are missing, and my vacumm lines prolly aret routed right. Anyhow heres the problem ive been driving it for 4 months and it doesn't seem to have anymore power than my 2.3l ranger, and it gets 15mpg at best, 12 mpg city, when you give it half throttle or full throttle throttle there doesn't seem to be much difference and the truck has no top end power over 1800 rpm it looses a lot of power, now I thought this was just how the truck is, then today I drove a 95 ranger the same as mine, only difference with it is is has the next generation dash in it and the intake on the engine is plastic and when I hit the gas this truck pulled way harder than mine, it spun the tires eveytime I got on the throttle in 1st gear and had power all the way to like 4000 rpm, my truck wont spin the tires unless I dump the clutch and its more like a chirp. All filters are new on truck and fluids. What could be causing this big of power drop and fuel consumption?

 

[UrbanRedneckKid]

Your fuel consumption is pretty much on par with most everyone else. 4.0s are thirsty.

Have you checked your fuel pressure?
Any vacuum leaks between the MAF and throttle body?
Any other vacuum leaks?

 

[ncsdaonex]

there are a few minor vaccum leaks idk how its supposed to be routed, and no didn't check fuel pressure

 

[AgPete139]

Not THAT thirsty.

Stock hwy is 20-21 mpg. I get 17.5 hwy on 35's and 4.88 gearing.

I would recheck my vacuum lines, spray down the MAF sensor, and check the plugs. Some people simply don't check gapping and readjust it (for free) when it comes to things like this.