CAR IDLES GOOD, BUT WONT DRIVE FORWARD

[45CHI]

I HAVE 2001 5.3L/LM7 STOCK STANDALONE LS SWAP WITH TRUCK INTAKE. ENGINE IDLES GOOD AND REVS AS HIGH AS YOU LIKE, BUT WILL NOT DRIVE CAR FORWARD. ::::ANYBODY EVER HAD THIS PROBLEM? ](*,)

 

[Doober]

Meaning...??? Does it stall? Does it just not move while in gear? Does it act like you're holding the brakes? If it still runs fine but doesn't move while in gear I say transmission.

 

[t5montecarlo]

Automatic? Is the torque converter properly engaged with the pump?

 

[Roller406Bu]

got enough fluid in the transmission? transmission cable even on? lot of could be's here....