In a A/T, they are usually a SLIP-FIT, but RUST is the problem.
One gallon of Muratic acid is about $7.50, sold at pool supplies.
With a brush, apply Muratic acid and keep it damp with the acid.
Better to nose-down, your block. (like into a spare tire & rim x2 or x3)
Muratic acid will....desolve the rust in a few minutes.
You got....a pipe wrench? Channel-Locks should work, too,
to twist it.
Really stuck?

You drill a hole, thread it (like #10x24) and install
a screw, to grab-upon, it orrr, go all the way thru it.
Same method you would use to extract the TB, shaft seals (#8 metal screws)
Defined here:
http://starquest.i-x.net/viewtopic.php?t=2599
You could, encounter other parts, that are RUSTED-TOGETHER.
Rear, rusted-on, brake rotors?

It is already drilled & taped, two places,
for a 8mm bolt....that pushes-off the rotor. (but remove the signal, tapperd,
phillip screw, first, with impact driver)

After 20 minuets of soaking them in Muratic acid. (recommend you paint them, next)
Note the pre-threaded holes x2.
REAL....Japan, cast iron! Not Mexico TRASH, iron!
Really rusted? MURATIC ACID IS YOUR TOOL!

(gloves & eye protection recommended)
Some say, Coca-Cola removes rust, too. (never tried it

)
Would a carpenter chiesel, get under that lip?
I grew-up in Chicago's, suburbs...I KNOW, ALL-ABOUT, RUST!
That is why I moved to the DESERT!
Psst...when I was a kid, I was trained to use grease and a shaft to remove
a pilot bearing.
A: it did NOT work, very often!
B: it makes a huge mess! (grease squirts, all-over the place!

)
C: If its a brass, pilot bearing, I chip-away the brass with a very, narrow,
sharp, chiesel! (cut a slot into it)
I also have a huge selection of.......DRILL BITS! (as big as 1.5"!)
Btw, last week, I made a costum, pilot bearing from sinterd bronze
for our Pro Drift Car.
