okay so my original 305 in my 92 took a dump and i bought a freshly rebuilt motor from a friend of mine thats a 350 bored .030 over with a towing/rv cam in it, it is a throttle body motor. the motors solid, and strong but i had to use my throttle body off of my 305 for it. so now when i'm driving (this is only sometimes) around 2000 Rpms the motor will spit and sputter and carry on, then right around 3000 rpms it runs fine. also, sometimes when the truck is in gear at idle it will want to die (its an automatic obviously). I have replaced the EGR valve. My questions are... first, could my IAC valve be causing this wanting to stall? also could the throttle position sensor be causing this sputtering in the top end? Do you think my throttle body should be thoroughly cleaned and have new injectors installed? and finally, my timing is set at 0 degrees avdvance, do you think with the towing cam in it i should advance it two degrees? please help