i just changed my carb, i went back with rochester carb same as what i had, but now it back fires through the carb, it didn't before maybe the timing was off ,,whats up ? i did see that the choke writing was upside down compared to the old one ,, does that matter ???

thanks

1958 chevy biscayne
235 6 cyl 1 barrel
2 speed PG tranny