I've recently pulled and replacedthe heads on my 1990, 350 tbi, and now it won't start. I have spark and fuel to the throttle body. I have also set the rocker arms to one turn past zero lash. I initially thought the timing might be out 180 deg., but have tried the timing both from tdc and 180deg. When I try to start the truck, it coughs and backfires through the throttle body, and has even thrown flames. The truck has sat for almost 2 years, and is old fuel, but it seems to burn all right in the intake
This one has me stumped. Any suggestions?