I just recently did an engine swap from a 4.9 to the 5.8 in my 1995 f-150. Its a standard cab short bed with M50d 5 speed manual transmission and 3.55 gears. Is basically just a stock rebuild with headers. Has great power at the low end and the truck pulls hard to 2500 rpm. Then power seems to fall off and it seems to have to work at it to get to 4000 where it stops climbing. Im just wondering if this is the normal power band on these motors or if the 2 inch "california smog legal" exhaust is holding it back. Any other suggestions?