Do you want to build the motor to have the experience? Or, are you thinking you'll save some money by doing it yourself?
And since I'm full of questions!! What's the budget size?

In many cases you can get a rebuilt long block ( or short) already completed and even get a guarantee with it. Another thought I have with a 79 block, it's probably a smog motor and not really a performance platform.

In any event, glad you're here and many SBC kinda guys will be along to offer you mucho info to help guide you.