Does the engine try to start but just doesn't catch.? Have you tried the following;
1. Fuel, do you have pressure (43psi)and flow at the fuel rails?
2. Spark, have you pulled a plug, hold it up to the block and crank the motor to see if you are getting spark.
3. Pull the distributor cap and check if the rotor rotates while cranking the engine. Is the rotor loose in anyway.
4. Assuming you have a MSD box. Are you getting a tach singal at the comuter. Won't start without it.
FFR #6641, Mk 3.1, 408W Stroker, Dart Block, Edelbrock Victor Jr Heads, Custom Hydraulic Roller Cam, Quick Fuel 750 CFM, Non-Donor, TKO 600, Center Force Clutch, 8.8" Detroit Tru-Trac, 3.73 Gears, S.S. Side Pipes, Polished FR500 Style Wheel, Big Ass Wilwood Brakes, VPM Reinforced 3-Link, Stainless Steel Braid Everything. POM Dec/2010 & Feb/2011.