Have a 66 GTO with a 1972 455. Just took it out for the first time this year. Stored it in November. Full tank of gas, fuel stabilizer. Ran fine today until I kicked in the secondary’s. It then started bucking and seemed to want to stall until I backed off. Pulled down a side street when all of a sudden it completely stalled. Tried starting it for about 5 minutes, cranked fine but would not catch. Finally like nothing was wrong it started. I drove about a mile when it stalled out again. This time it restarted in about a minute. Drove home about 3 miles and no problem. I let it run at the house for about 15 minutes without any issue. Any ideas why it would act up when secondary’s kicked in, then stall. It ran fine last year. Put in a new fuel filter last year. Thanks in advance for any help.