Gas In My Oil!!!

i have a 97 s10 blazer 2 door, i just got done puting a new engine in off a 2001. it wouldn't run right at all, so a buddy of mine mentioned a problem he ran into with gas leaking into the oil, and sure enough, I pulled my dipstick out and it reeked of gas. i drained my oil and put some fresh stuff in there, but it still wont start, there had to be a good 1 to 2 quarts of gas in there when i drained it, i didn't run the truck with it in there too much, maybe i put 1 mile on it, if that, so im not too concerned with motor wear, i just cant figure out where its coming from, and how it would get in my oil, i pulled out the injectors, and the actual hoses themselves are fine, the motor has low miles on it, so i kinda dont think that whatever the shit is its from wear and tear, i would think that any problems that i would have would have come from the engine swap, but i dont know, does anyone know how gas could get into my oil, and what i should look for? PLEASE HELP ME!

the only time (that i could think of) oil and gas would come into contact with each other would be in the combustion chamber. but your piston rings should
prevent gas from flowing down into the motor. maybe your rings are worn. i think you could do a compression check to to resolve that. im guessing.
thats the only place i can think of that they would mix.

Also if you didn't put your injectors in the right order you could be dumping too much fuel which will drop down past the rings (worn or not) into the oil... This is very dangerous to your cylinder walls if they get washed.

Remove top of intake. The gas hoses, or gas pressure regulator could be leaking.

how would a head gasket cause this problem? if the motor sat for a while you may have an injector stuck open. this would cause fuel to dump into the motor causing cyl. washdown. just an idea?

The 2001 motor is a little different than the 1997 engine and I hope you swapped in the 2001 computer as well.