Blinker issue new painless wiring

[TheRedTruck67]

Well guys ran into a little issue. I recently just got done installing a painless wiring harness in my 67 c10. Everything works Except, when i turn my back blinkers (front blinkers working perfect) on with the headlights off they work fine. But when i turn the headlights on only one blinker works. The weird think is when i take out the bulb to the blinker that is working & install it on the one none functioning it works. So i figured it was the bulb took a bulb off a 72 i have here & it works when the headlights are off only. But once again when i put the bulb that originaly works on that side it works perfect. Went to go pick up some new bulbs but didnt noticed they say 2057 & the lightbulb thats working is 1157 but it fits perfect & works but once again only with the headlights off. Do i really need the exact same bulb ? Or could it be a ground issue ? Sorry this could be confusing to read, but explained it the best way i could. Thanks in advance guys !