I'm looking at Holley Carbs. I wanted just an 850cfm Double Pumper, but some people have said the HP950 (or maybe it's 950HP?). Is there a difference in these, and if so can someone tell me and maybe give me the P/Ns? (I ask because my parts guy couldn't find it). This will be for my upcoming 454. Thanks.

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Holley # 0-80496-1 best carburetor that I've ever bought.

Holley # 0-80496-1 is the one. You will definately like it on your combo. They come jetted pretty close out of the box, but I had to go up 3 jet sizes square on mine but I'm at sea level. Go for it.

So it's called the 950HP or whatever, but it's just a 950CFM double pumper?

Don't be scared off by the 950CFM rating. It has a narrow venturi like a 750 and a base plate like an 850 size and has a high velocity through the venturies for very fast throttle response. It works well. I'm impressed with mine.

Taylor,

It's called Holley's Pro-Series HP 4150 carbs. The part number for the 950 is 0-80496-1 and Holley "claims" 950cfm but in reality it wet flows closer to 820-830 cfm.

It's basicly a 750 main body with an 850 base plate. A real nice carb.

Did I remember correctly from one of your last posts that this will be your daily driver? If so you might want to reconsider using this carburetor. NO CHOKE . At least on my car this carb is very cold natured. Don't drive mine in the winter much, but start it every now and then and it is difficult to start and keep running. (pain in the butt last night with 20* temperatures)

"If" this is going to be a true daily driver I would think about using a re-worked Q-jet.

This is a bit off topic but..I am finishing up my 396/4 speed installation..I went with a new Holley 750HP. I just got the timing dialed in over the weekend. I will second that this carb is a bit cold blooded..it is taking me a bit of getting used to, firing the engine over and having to feather it to keep it running, then finding the sweet spot to achieve a fast idle when cold. I tried it again last night, it was about 35 degrees F here, and with about 4 pumps of the pedal she lit right off, then some feathering, and finally got a fast idle. I realistically wont be driving much in the cold, so Im not too worried about it.

As for performance..I had my engine shop dyno test my motor back to back with a regular 750 DP, and also with an 850DP..the 750 HP made the most power and best torque curve..not a dramatic difference, but it was there, so I went with it.

The HP's have no vac ports either. Excluding the 750 HP.

For the price, you can get a worked 750 dp the same way. Just ask for them to leave the choke on and run a K&N substack. Or is Comp making it now?

You can be really stealthy and run a 3310 modded the same way. But you have 4.10's so not the optimum choice.

AFA chokes go, you can get away w/o them in CA. Never had one...But it's hard on the rings.
I've found if you just imediatly go to 1500-1700 depending on temp, that you only have to let off the pedal to maintain rpm as the motor warms up.
Little to no feathering needed. Which is the hardest on the rings.

And my 850 was the worst on a cold morning...

Holley has a 850 VS elect choke btw. Came on vettes. Still cheaper than a 950hp. But more than a 4781. My catalogs a 98 so they may have discontinued it.