Stronger/tighter throttle return springs

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Joined
Dec 10, 2017
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Georgia
My Car
1973 Mach 1 "Q Code"
Here's my setup, I used the factory 4V bracket with a couple spacers underneath to get the cable aligned. I'll make a proper one piece spacer this winter.

View attachment 65743
Thank you for the pic, that setup looks great. I will get mine leveled out. Hemi, I don't see any other springs on your setup, do you have return springs or is it removed for in the picture. Thanks.

Tom
 
Joined
Jul 27, 2021
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East Texas
My Car
1971 Mustang Mach 1 M code 351 4 speed
Just a pretty much stock cam. Melling MTF2. It wasn't the cam that was the issue, this 670 Street Avenger carb ran really fat out of the box. It needed more air in the mixture and that is why the specialist drilled the holes to enable the transfer slots to be set in the correct position. This has been hashed out many times on here. Bottom line is it worked for my engine. The AFR is very close to being spot on now.
That is a very mild cam, I really find it very interesting that you had to drill the throttle plates to get the idle AF ratio right. You really should not have to drill holes in a Holley carb that is on a very mild engine build. Holley must be doing something strange these days. I never saw that back when I was really into this in the mid-80's through the early 2000's.
 
Joined
Sep 12, 2015
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Location
SW Ontario
My Car
1971 Mustang Mach 1, M code, 4 speed.
That is a very mild cam, I really find it very interesting that you had to drill the throttle plates to get the idle AF ratio right. You really should not have to drill holes in a Holley carb that is on a very mild engine build. Holley must be doing something strange these days. I never saw that back when I was really into this in the mid-80's through the early 2000's.
Yeah this subject has been hashed and bashed on here for a long time now.
I don't believe it is to do with the cam at all, but the Holley Street Avenger 670 carb that is known to be rich out of the box. The guy who did my carb set-up is a locally well known tuner who works largely on race cars (Mud puddle stock cars I call 'em).
What ever the reason, this worked. I no longer have excessive gas smell or raw fuel dripping out my tail pipes. It allowed the transfer slot to be set square where they ought to be. Before that, the primary plate needed to be cracked open beyond that just to get it to idle, therefore needing more air.
This combination works for this engine and that's all the matter to me. It idles well and pulls like a train.
 

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