Always buy a good carb.

[Ziegelsteinfaust]

I have had the cheap Holley 750 vacuum secondary with jets on both ends. My engine is a 5.7 or 350 2nd generation LT1 with AFR 190E heads, gmpp intake, and a Pertronix distributor. Compression is 10.7-1, and a Comp 306 cam.

No matter how I tuned it never felt right. Not bad, but not right. Although it was fine for DD. Which is where I was aiming.

Well today I put a original Demon 750dp street model on it, and rough tuned it. Which I just rebuilt this week to put around on for fun. While it is running pig rich at 11.5 afr pretty much everywhere. Which I returned the 4 corner idle to lean out a hour ago, and took a jet out. I have to see where sits at tomorrow morning.

It honestly felt like I picked up 10-15 hp, and the responsiveness was just up everywhere. Plus the afr swing was much tighter then with the vacuum secondary. So if my thoughts work out I should be able to atleast match or maybe even beat its current highway mpg average. City will always be in the toilet due to the cam selection.

Besides the jets. I am also going to dial in the accelerator pump since this carb seems less dependent on it vs the Holley 750 vacuum secondary for good drivibility.

So to whomever is still into carbs like I am. Always get the best one you can afford. You won't go wrong especially at tip in for passing power.

[The Rocknrod]

I have a Street Demon 625cfm. Pretty well known around the net that they come fat which mine was. I changed the jets to 78's and played with the metering rods and now get 16mpg. For my engine and all I'd say I'm pretty pretty happy.
I like the passing power. Around here your either being passed or passing.

[GASoline71]

Originally Posted by Ziegelsteinfaust

I have had the cheap Holley 750 vacuum secondary with jets on both ends.

Since when is a Holley 3310 with a rear metering block in it cheap?

Gary

[Ziegelsteinfaust]

Originally Posted by GASoline71

Since when is a Holley 3310 with a rear metering block in it cheap?

Gary

It was the cheapest version of that model made. I added the performance parts to it, and while great in a 95 Vortec motor. On my LT1 it always had issues.

If my reading of carbs is right. Every sub model gets different air bleeds among other details. Which in my case never let it perform right. Work good yes, but not perform.

[GASoline71]

Originally Posted by Ziegelsteinfaust

It was the cheapest version of that model made. I added the performance parts to it, and while great in a 95 Vortec motor. On my LT1 it always had issues.

If my reading of carbs is right. Every sub model gets different air bleeds among other details. Which in my case never let it perform right. Work good yes, but not perform.

The 3310 is a performance carb. They are pretty much all I use. Either that or an 1850. Sorry you had issues with them as they are great carbs that are extremely tunable.

Gary