The 2.8i was a different league to marginally more powerful than the 2.8 carb. And fitting the carb from the 2.8 onto the 2.3 made quite a difference. Especially with the 5 speed manual
FTFY. And K-jet on a relatively large engine meant it had
horrible throttle response - as if the cable was made from elastic.
The 3.0l and 2.8 have the same mechanical faults(timing gears, oil pump drive, weight) but are either torquey but breathless, or gutless and revvy. Each has its own faults, like weak rocker adjusters on the 3.0l and the 2.8's waterpump.
What you actually want is the 12v 2.9, which gives both with decent fuel economy mainly due to the management but is a straight swap for a 2.8(the 3.0l is a completely different architecture although it's dimensions are similar). This all largely academic now that all of these engines are obsolete, hard to find, suffer from the
classic Ford tax and their power is easily achieved by a cheap 2.0l four cylinder - 1.8 VVC K-series is 160bhp and about £250 for example