If you don't care 'bout gas prices do the 350,your s10s 5-speed will bolt to it.The 4.3 is basicly a 350 with 2 cylinders chopped off,just get the motor mount swap kit.And while the beds off it's time for a HUGE C-NOTCH dump that thing,just my .02 cents........btw the '94 s10s have a cooler...