The fluid catalytic cracking (FCC) behavior of compound types present in the > 650 degrees F resid from Maya crude was investigated. Distillation and liquid chromatography were employed for separation of selected compound type fractions from the resid; the resulting fractions were then cracked using a bench-scale FCC unit. The FCC behavior for each compound type was defined in terms of the resulting product distribution (yields of gas, gasoline, etc.); sulfur, nitrogen, nickel, and vanadium partitioning; and, in selected cases, gasoline composition. Results obtained from Maya fractions were compared to those obtained from earlier FCC studies of compound types from Wilmington, CA, and Brass River, Nigeria, >650 degrees F resids. A conceptual model was proposed that adequately predicted FCC product slates obtained from >650 degrees F neutral fractions from Maya and the other crudes. An important premise of the model was primary production of gasoline and C-3/C-4 gases from alkyl side chains and acyclic paraffins in feeds with concurrent conversion of aromatic and naphthenic cores to cycle oils. The product slates calculated from the model agreed well with those determined experimentally. Highly aromatic feedstock constituents presumably formed only coke and light gases. A calculation of hydrogen transfer resulting from cracking indicated no significant hydrogen exchange between aliphatic gasoline or C-3/C-4 gas precursors and naphthenic/aromatic cores. Implications of the model toward improving FCC feed pretreatment and performance evaluation are discussed.