holley 650 dp on 383

[68c10owner]

Originally Posted by donpr

Im not concerned about gas mileage, its not a daily driver.

Look up the Quick Fuel Slayer 750cfm vacuum secondary carb. If you don't want the qjet I'd go with this carb. Similar to the 3310 but more adjustable.

[donpr]

Is this the one or the 600 ?
http://www.ebay.ca/itm/Quick-Fuel-Sl...cd4076&vxp=mtr

[68c10owner]

Originally Posted by donpr

Is this the one or the 600 ?
http://www.ebay.ca/itm/Quick-Fuel-Sl...cd4076&vxp=mtr

That would be the correct one. The 600cfm might work ok as well. Would give better mileage than the double pumper but you mentioned not caring about mileage so thats why I suggested the 750cfm. For this engine stay away from double pumpers all together regardless of the cfm rating. This is a very mild engine that is going to make a lot of low-mid speed torque. A vacuum secondary carb is the best fit for a street/strip set up. If you needed mileage the qjet is best. Drag strip only then the double pumper will work.

[MikeB]

Originally Posted by Tom

Your not factoring in the massive amount of fuel shot in[doublepump= double shot of gas] every time the accelerator is advanced at all.

I didn't consider that. But doesn't the rear pump squirt only when the linkage progresses to the point where the secondaries start to open?

BTW, back around 2002 I ran a 650 VC Holley modified by QFT on a mild 383 with a Crane cam (210/210; .470"/.470" lift with 1.6 rockers), Dart 180 heads, and Performer RPM intake. It worked well and let the engine rev to 5800 RPM or so, which was 600 RPM higher than with a Performer 2101 and Edelbrock 600 carb. However, I probably didn't rev it that high more than twice! To me the beauty of a 383 is low- and mid-range torque. So you don't have to rev it as much as a 350 to go fast.

[68c10owner]

Originally Posted by MikeB

I didn't consider that. But doesn't the rear pump squirt only when the linkage progresses to the point where the secondaries start to open?

BTW, back around 2002 I ran a 650 VC Holley modified by QFT on a mild 383 with a Crane cam (210/210; .470"/.470" lift with 1.6 rockers), Dart 180 heads, and Performer RPM intake. It worked well and let the engine rev to 5800 RPM or so, which was 600 RPM higher than with a Performer 2101 and Edelbrock 600 carb. However, I probably didn't rev it that high more than twice! To me the beauty of a 383 is low- and mid-range torque. So you don't have to rev it as much as a 350 to go fast.

You are correct about the secondaries but they start to open pretty quick because they are set up with the primaries with mechanical linkage where as a vacuum carb relies on engine vacuum or open them.

A 600 cfm carb will starve a 383 if it`s anything more than stock and you are trying to rev it, and 5800rpms isnt high. It all depends on how the engine is built as to what rpm it will need to turn. The same cam in a 350 and a 383 will have 2 different power bands. The bigger engine will be done sooner.