I just brought home a rusted-out, bondo'd '76 Celica. I'm guessing it still has the original 20R; I'm not entirely sure becasue the sticker on the valve cover is missing.
It idles OK, but hesitates when the gas is punched. It also backfires a little while coasting down hill (possible exhaust leak?) and diesels when the ignition is turned off. The carb appears aftermerket, but is clean. It doesn't look like any of the emissions are hooked up (but they are present under the hood).
I haven't checked the timing or vacuum yet. I'd like to address the hesitation first. Does anyone have any recommendations where to start?

I haven't checked the timing or vacuum yet. I'd like to address the hesitation first. Does anyone have any recommendations where to start?