Alright here we go, i have a 355 carb. in a 93 pick up 4x4 the engine is a zz3 that was built little better than factory did being they left the rod cap loose anywho my problem is this when i park or neutral i can get the engine to rev relatively well but it has a hard sputter when you really stap the gas pedal if you ease on the pedal it cranks rpm's no problem it will almost die if you dont let up on the gas when you hit it hard. now when you put it in gear reverse or drive it will bust up really bad unless you very lightly increas the gas but if you dont it will back fire throught the intake. i have a brandnew procomp hei distributor and 8.5 accel wires plugs are new but the truck has been sitting for 2 yrs i have tried the timing all over the place 0 degrees all the way through to 30 degress did best around 16 degrees the carb i'm running is too big i think stock carb off a ZZ502 which is a 850cfm single pump duel inlet electric choke. initialy i was think the carb is to much which i still do so i disconected the vacum secondary and it improved tremendesly when in park or neutrual will rev hard no problem but in gear whole another ball game what am i doing wrong or over looking. park idle runs great in gear it's crap could my plugs be the problem along with way to much fuel.?