If you are looking for this functionality, it is rarely a standalone mod and is usually found as a toggle within "Utility Clients" or specific building mods: Orange's SimpleMods:
The is a lightweight, often Forge-compatible, client-side modification that removes or drastically reduces the delay in block placement when holding down the right mouse button (or your assigned "use" key).
: Overhauls placement logic to mimic Bedrock Edition, removing delays and locking placement direction to prevent accidental double-placing. fast block place mod 1.8.9
Fast Block Place Mod 1.8.9: The Ultimate Guide for Minecraft PvP and Bedwars
Using a Fast Place mod on the wrong server can get you banned. If you are looking for this functionality, it
Master the Game: The Ultimate Guide to Fast Block Place Mod 1.8.9
: Offers "Fast Right Click" as one of many redstone and building utility features. Accurate Block Placement Reborn Master the Game: The Ultimate Guide to Fast
For competitive bridging methods like Godbridging, Moonwalking, or Breezily bridging, the standard 4-tick hold-down delay is too slow. Players must either achieve incredibly high manual CPS (14–20+ CPS) or find ways to remove the client-side restriction. What Does a Fast Block Place Mod Do?
Ensures blocks are placed precisely where you are looking, even at high speeds, preventing "ghost blocks" or misplacements during fast bridging.