I notice the difference more when the Jacob's ignition has been disconnected for one reason or another. With my mod's there is a definate difference in the throttle response as well as the mpg's, about 2 miles less per gallon w/o it as well as higher smog numbers.

You are right about the Jacob's being little bang for the buck by itself, but then again any mod by itself to the 3.0 produces very little gain.

More than tread lightly. Leave it like you were never there, nor anyone else.
'90 X-cab 4.88's 33 BFG AT's, rr ARB, Headers, Ignition upgrade, cold air induction.
'91 X-cab 5.29's 315's BFG MT's, rr ARB, custom bumper and flatbed