I have a rebuilt 351M but the carb is problematic. Would it be practical to replace the Motorcraft 2150 with a Holley 500cfm 2brl. 4412S? Idling rough.

 

No, figure out what's wrong first. 2150s are great carbs. If it's not idling right, it's because it's not dialed in or something is wrong elsewhere. The Holley wouldn't be any easier to tune. I'd take a shot at dialing in the carb, and giving it a rebuild if it's time. Also check for vacuum leaks. Often times a carb is thrown out when the problem is really a leaky power brake booster.

 

the brakes seem to be working normally. Thanks

 

whats the cfm on a 2150?

 

It depends on the venturi size; refer to the sticky on this forum.

By the way, this (unrelated) thread is over 5 years old!

 

https://www.ford-trucks.com/forums/1...eral-info.html