Holley 600 model for 258 (3bbl)

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   Saw this on YouTube and found it interesting. Guy modified a Holley 600 vacuum secondary carb to a 450 by blocking off one primary. It's installed on a hopped up 250 in a 65 Chevelle wagon, about the same size and weight of a  63-66 Classic. Says gas mileage increased but throttle response and power is better or equal to a 500 Holley 2 bbl with progressive  linkage (hard to find). Since the 600 Holley is easy to find and cheap used, this would be a great 232/258/4.0 option. A few have successfully run 600s on hopped up 258s, but those are pretty radical builds. Streetable, but more than most would build. This 450 model would be much better for a good hopped up street six. You will need a 4v intake though. It should work ok on a stocking 258 with a 4v adapter.  You lose some flow with an adapter, but shouldn't hurt a street engine much, would hurt WOT flow, and you wouldn't use that much.
I'm on my tablet and can't figure out how to copy the link to here! 
Search "Holley 600 3bbl" in YouTube  to watch. 

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farna Members Profile Send Private Message Find Members Posts Add to Buddy List Supporter of TheAMCForum Moderator Lost Dealership Project Joined: Jul/08/2007 Location: South Carolina Status: Offline Points: 19672	Post Options Post Reply Quote farna Report Post Thanks(0) Quote Reply Topic: Holley 600 model for 258 (3bbl) Posted: Feb/16/2019 at 8:21am
	Saw this on YouTube and found it interesting. Guy modified a Holley 600 vacuum secondary carb to a 450 by blocking off one primary. It's installed on a hopped up 250 in a 65 Chevelle wagon, about the same size and weight of a 63-66 Classic. Says gas mileage increased but throttle response and power is better or equal to a 500 Holley 2 bbl with progressive linkage (hard to find). Since the 600 Holley is easy to find and cheap used, this would be a great 232/258/4.0 option. A few have successfully run 600s on hopped up 258s, but those are pretty radical builds. Streetable, but more than most would build. This 450 model would be much better for a good hopped up street six. You will need a 4v intake though. It should work ok on a stocking 258 with a 4v adapter. You lose some flow with an adapter, but shouldn't hurt a street engine much, would hurt WOT flow, and you wouldn't use that much. I'm on my tablet and can't figure out how to copy the link to here! Search "Holley 600 3bbl" in YouTube to watch.
	Frank Swygert

farna Members Profile Send Private Message Find Members Posts Add to Buddy List Supporter of TheAMCForum Moderator Lost Dealership Project Joined: Jul/08/2007 Location: South Carolina Status: Offline Points: 19672	Post Options Post Reply Quote farna Report Post Thanks(0) Quote Reply Posted: Feb/18/2019 at 7:08am
	Got on my computer this morning -- here is the link: https://www.youtube.com/watch?v=iXdFLCIz-BA
	Frank Swygert

mjt084 Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Fan Joined: Oct/25/2017 Location: Australia Status: Offline Points: 9	Post Options Post Reply Quote mjt084 Report Post Thanks(0) Quote Reply Posted: Feb/19/2019 at 1:41am
	Very interesting Farna, would love to see some more detailed instructions on how to make the mods!