I just got done swapping my L03 for a vortec headed 350 with a Comp XE262 cam. It starts up fine and idles kinda rough(which I expected from a cam with 110 lobe seration) for about 10 seconds and will then just die. If I give it gas, its seem to want to stay alive. I have the Hypertech Thermomaster chip that I had with the L03 still in it and just a stock TBI with the Ulitimate TBI mods and the FPR made adjustable. I've played with the timing a little just by turning the distributer but can't seem to find anything that it likes. Any help would be great.

 

Check your vacuum lines for a leak somewhere