Street Demon or Edelbrock AVS2 or ?
When I ran stock 340 I had a Holley 600 on there for years that I bought new. Fooled around with jets, accelerator pump cams, vacuum springs ect. Got it to run really good. Then when that carb got old and tired went with a 650 Edelbrock AVS. Had to put bigger accelerator pump nozzle and fool around with jets/rods a lot but got that running good as well. The Edelbrock I liked cause it had the original carb look to it and it ran really good once dialed in. I think Holleys get a bad rep cause ppl buy old ragged out used Holleys and not able to get them to run right.
As far as Edelbrock getting heat soaked yes that an issue but if intake cross overs are blocked and you run that Edlebrock gasket thats made to insulate from heat its manageable.