Rough cold starts, but then runs perfectly

[Mister-B]

I've got a '69 C20 that has a rebuilt 350 V8. It runs and idles perfectly, but it is a little hard to start the colder it is. I have to pump the gas a bit while I crank it, and have to rev it while it warms up. Sometimes it dies if I don't rev it enough while it warms up. But then it runs perfectly. It idles and accelerates great and I wouldn't change a thing.

Do I just need to work on my technique to start it, or is there something I need to adjust or fix?
Posted via Mobile Device