Hello out there! Got a 1933 chevy 207 that hates the cool weather. This is I understand the first year for heat risers. The truck runs great in warm to hot weather but complains terribly in even slightly cool weather. Below 50 degrees it has trouble warming up and below 40 barely can be driven as it acts like it is starved for fuel even with choke pulled out. The heat riser is in open position so it should be heating the intake. Any ideas? Thanks a million! Ken