just a few ?'s

hey guys, been a while since ive been on here now i have a few questions lol. 1st of all, when i get out of college for the summer and start workin, i plan to buy a LCE header for my 2.7 tacoma. i was wondering if anyone has a header on their 2.7 and if they could tell a noticeable difference. 2nd, i was wondering if you could change the rev limiter to like 6500 rpms, changing the hp and torque curve to meet the new limit and if you could do it without changing to more aggressive cams. 3rd, has anyone done a 1UZ swap in their tacoma? i know lexus/toyota engine swaps are becoming popular, and wanted to know the trouble you have to go through to make that possible. a 4.0 250 hp V-8 would be awesome in a tacoma! thats just a long term thought...im def. not financially stable yet to think of a project like that lol