2.8 MAN I HAD ONE THAT BROKE THE CRANK IN HALF AT 4000RPM BOUGHT A NEW CRANK AND THE CAM BROKE LEAKED OIL THE WHOLE TIME SORRY IT THE WORST MOTOR I HAVE EVER SEEN I WOULD HAVE RATHER HAD THE 2.5 IN THE S10 THAN THAT THING.

ON THE OTHER HAND THE 3100 IS NOT A BAD MOTOR I HAVE ONE IN MY GRAND PRIX BOUGHT A FORGED CRANK, TRICK FLOW PISTONS, ARP RODS,EDELBROCK HEADS, CRANE CAM, AND CANT REMEMBER WHO MAKES THE TURBO'S BUT TWIN TURBO'S.
IT FLYS MESSED THE TRANNY UP IN 3 WEEKS HAD IT MODIFIED NOW IT SPINS THROUGH 3 OF THE FOUR GEARS I WOULD SAY IT'S A GOOD MOTOR.