k14 will spool up nice and fast. they are good turbo's. the "fatter ones" are mostly t3's. bigger. more flow. but slower to spool. if your not making a race truck then the k14 will be your best bet. straight pipe is the way to go. 2.5 all the way. and if your a slally you can put a muffler on it. the pump is not that bad. it does what it needs too. you can still get plenty of fuel out of it. i'm running it on a 80 rabbit truck with a fresh in chassy over haul. (rings and new head, turbo injectors, and eco pump, 210mm clutch) set up to smoke lightly at almost to the floor. 1.6 na. mech. head. gas intake manifold. cold air intake. 2.0 gas exhaust manifold. 2.5 in. exhuast with a glass pack muffler.. its a runner.