When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
What you have is a performance engine (as built) and you want to restrict the engine for normal street use. It is going to take a lot of ciphering to get it to act right.
There is much tech info on the inner-screen (be wary of sources) to help you calm it down. It is do-able but you have to source the correct info. HOLLEY offers a plethora of inforrmation.
BTW - What intake manifold are you using? Stock ignition or something fancy? What is the CARB LIST NUMBER? Was it bought new or an older model?
Intake is a Blue Thunder 4 bbl aluminum. Pertronix igniter 2 ignition Holley 4160 0-1850S it was bought new. Done the calculation in 500 rpm increments from 4500 to 7000 rpm using 75 and 85% volumetric efficiency. It never comes out needing more than a 520 cfm carb. here is an example. 302 cu in x 5000 = 1,510,000 / 3456 = 436.92 x .85 = 371.3 CFM. Even if you achieved 100% volumetric efficiency it comes out as needing only 436 cfm of carb. And that is without taking any altitude into consideration. Mine will rarely if ever see over 5K on the tach. Everything says 600 is to big. Now if you were talking drag racing and you only did WOT runs a 600 may be fine. IMHO
Last edited by skidoorulz; Apr 5, 2026 at 10:45 AM.
On the BT INTAKE, did you find that new or used? I think BT stopped offering the FYB intake but am not ceratin.
Intake was brand new. But you keep using a 350 for cfm calculation. Lets talk apples to apples. Do those same calculations using the engine I am asking about and the numbers are what I have been saying all along. You keep saying i have not dialed in the 600 and I have tried everything I can think of to get it dialed in. The only thing you have provided is 350 calculations which is not what I have. You say a 600 isn't to big but you haven't suggested anything that can help me dial in the 600 as you say I need to do. I have answered every question you have posted and still nothing from you on what I should do to dial it in. I looked at your avatar and realized I just might be dealing with an elbow bending barstool master tech! Thanks for wasting my time. I really thought eventually I might pry something out of you but I give up!
I hope you will let us know how that 390 cfm carb works for you. It should be fine for cruising.
I will update this. I have a slightly used 4160 on its way but it has been sitting for some time so I am going to clean it and kit it. Start with factory settings and go from there.
Last edited by skidoorulz; Apr 6, 2026 at 10:43 AM.
I am not there to hold your hand. I also do not work for free.
You also did not move your computer close enough to the truck for me to see anything.
For you to properly dial in a crab, I explicitly told you where to find the TECH MATERIAL to do so.
I am not your mommy or girlfriend.
DRILL SERGEANT - "Trainee, did your parents have any children that lived?"
TRAINEE - "YES DRILL SERGEANT!"
DRILL SERGEANT - "THANK GOD THERE WERE SOME SURVIVORS!"
Go have another beer and zip it! Maybe the drunks at the bar are impressed with your ability to talk in circles and not say anything but I am not! If someone pays you one red cent for your advice you are over charging them. If my thread has done anything it has exposed you for what you are, just a talking head that knows nothing.
Last edited by skidoorulz; Apr 6, 2026 at 09:15 PM.
OK for those who are wondering. I got the 390 CFM carb. It is a model 8007 4160 vacuum secondary carb with manual choke. It had 51 main jets in it. 65 power valve and the accelerator pump cam was set in the number two position. Fuel screws were 3/4 turn out. I looked up factory specs for that carb and that is how it came from Holley with the exception that Holley sets the fuel screws at 1 1/2 turns out. I put a rebuild kit in it and bolted it on the engine. After the bowls were filled it started right up with no use of the choke. After about 30 seconds I let off the pedal and it idled at 600 rpm with no choke cold. Once it warmed up it now idles at 700 rpm. With the 600 on it I had to choke it to get it to start cold and had to run 1/4 to 1/2 choke just to keep it running without dying till it started to warm up. Also with the 600 I could never get it to idle below 800 rpm decently and at 600 rpm it would die. Sitting in the garage at idle there is no hesitation when you mash the throttle. I would take it for a road test but it is raining out. Driving it will be the real world test but as of right now it does everything better than what the 600 did. Once I drive it out on the road and around town I will let you know how that went. As of right now I am impressed with the difference!
New update. It quit raining so I went for a drive. I could tell it was way to lean. I got on the interstate, and I could feel it sputtering at highway speed. If I pulled the choke out part way it would quit sputtering. I went home and put the next size jet in that I had, a 61. Went back on the road and it run down the road fine probably rich though. I have ordered a 57, 58 and 59 jets to try. The Holley teapot carb which is approx 380 cfm came with a 57 jet from the factory on the 292. I will start there and go up if need be.
So you still had to calibrate the new out of the box CARB to your application?
Funny how that works ...
Who said it was new? Never said that! It is a used carb if you could read you would see where I said I kitted it! I gave the numbers of what was in it to let everyone know that this carb was set up stock with the exception of the fuel screws being 3/4 of a turn out instead of the 1.5 turns out the factory would have sent it out as. I also reported back how it ran on the highway to let everyone know that may put one on a 292 that the 51 jets are not enough even at 3900 feet. I am providing valuable real world feedback for this carb and the 600 which is to big. That is something you never did, all you did was run your mouth and gave nothing of value! Anyone with a brain which you obviously are lacking knows that jetting will more than likely need to be changed to dial in a carb, which I did over and over and over on the 600 and it never worked!. I calibrated the crap out of the 600 for a long time. This 390 used right out of the brown box the man that sent it to me put it in runs better set up as the way the factory made it than the 600 ever did! I will continue to fine tune it and get it perfect which never happened with the 600. I will continue to give information of what I find. So when I post you can just scroll on by and keep your useless comments to yourself! Maybe you impress the drunks at the bar with your barstool master teching but you don't impress me and I am sure many here are just laughing at you and not impressed at all.
Last edited by skidoorulz; Apr 14, 2026 at 02:29 PM.
