i have a 94 firebird formula the engine is misfiring i changed plugs and wires cap and rotor it shakes a little in park plus i can smell fuel while driving when she starts to misfire if i give it a little gas she's fine atleast until cruising speed then the engine will make a deep bellowing sound start to stutter and bogg down please help me

Maybe a bad Optispark distributor. They have been described as less than reliable. Replacing the cap and rotor is sometimes not enough.

did it shake before you changed the plugs and wires, or did it start doing it right afterwards?
are all the wires in the proper terminals on the cap? pushed onto the plugs all the way? hitting the exhaust manifolds?

it shock before i changed them the old cap was cracked in some places thespark plug wires were bad if you bent them they cracked in two another question my mechanic said if he changed the distributer for me he has to charge me xtra cause he has to program it am i being ripped off!!

ok,, first off..
try to break up your sentences. with periods. or commas..
second- no, you don't need to "program" an optispark- but you do need to tear everything off the front of the engine to get to it, which takes time.
but i'd check everything else before throwing another few hundred $$$ at the problem and hoping it goes away. there's gotta be someone on this board from your area- maybe you can meet up with them and get a free second opinion.

find the dead cylinder...you can use a digital infra red thermometer like a raytek, or pull individual plug wires to find which cyl isnt contributing to the party...(no power)then look for vac leaks over that cyl, bad opti, burned or cut wire, bad plug outta the box, burnt valve,,,,,so on so on...but at least you know the proper cyl...that`ll narrow down the search a lot...

if the opti is going it'll throw a code most of the time
pull the waterpump and pull the opti
a little moisture in the unvented (92-94) will cause carbon tracking like mad so I've always replaced the whole unit

I'd agree with double/triple checking the terminals and wires, opti wires plug in deep and are unique if I remember right

have the codes scanned lotta places do it for free, worth a small time investment