Stuck Throttle / carb rebuild options

[JointTech]

I dont really drive the truck.. Just start it weekly and drive it around the parking lot.

Yesterday i let it warm up a little and while driving stomped the throttle. Probably only 3/4 throttle.

I let off the gas and it didnt feel like it was slowing down. Fortunately the brakes are stronger than the throttle and i was able to slow it down. It seemed to be idling at 2000rpm or so. I put it in neutral and kicked it a few times to see if the fast idle was sticking or something. It still didnt throttle down so I turned the key off (expecting a massive bang that didnt happen)

Today I went out to get the numbers of the carb and started it up. No problems. Fast idle seemed normal and it kicked off when I tapped the gas.

So what caused the sticking yesterday?
I played with the throttle cable and spring and they seem ok and not bound up.



second is carb options. I wasnt to rebuild it myself but really cant have the truck not running for days because my office complex HOA are nazis about non running vehicles.

So I was thinking of just getting a reman from guarenteedcarbs.com for less than $200.

Then I started thinking about a holley or edelbrock instead. But I plan on swapping to a big block in the next few years and am not sure the carb can be used on a BB?

On this SBC 350 if I get a 600 or 750cfm am I going to bog out the little 350, or will I be underfeeding the BBC when it comes? Can I just swap the carb onto a new engine?

Current carb: 17059203 2278 CBB
I think its a quadrajet with no california emmisions, built in 1978 for a 1979 chevy with a manual trans.