which intake should i use?

I agree about more converter. That cam will BARELY be into its torque curve at 3K. I'd go 4200 if it was me. You can cruise around town all day long on a modern 4200 locking up at 1500 but scream when you pull it up and launch against the converter. That's what it's gonna need. Consider this. The stock 340 high stall converter was around 2500-2750. 3000 is barely more than a stock 340. That Thumpr cam is HUGE in comparison.