I appreciate all the info. I have been tuning on carbs for a couple years now. I am by no means an expert, but I have read a couple books on them including the David Vizard version of the book above. I'll look into buying that one as well.
The secondary tube mod is used on the street avenger because it has trouble opening the secondaries. Specifically on the 770 version. The smaller version does not have this issue. It is essentially enlarging the signal hole from the primaries to the secondary vacuum pod. Holley used to make this a standard feature, but from what I assume is cost savings, they stopped doing it. It helped quite a bit along with tinkering with the secondary spring, though. The secondaries used to open way up in the RPM range, even with the lightest spring.
The guy selling the Pro Systems carb has the spec sheet. Based off of it, it would be a decent fit for my set up, but would still need some tinkering.
The street avenger does not have replaceable air bleeds but I am in the process of changing that. I ordered some blank air bleeds and I am going to drill/tap to install them. I'll at least be able to fine tune it a little more. As of now it's tuned pretty well. It doesn't have repalaceable PVCR's, though, which is unfortunate.
I have a vacuum gauge, and a wideband o2 as well. They definitely help with tuning. I'm not so much having a hard time getting it tuned right as I am deciding on whether or not a mechanical secondary is a better fit for this set up in general. I also like the additional adjustments that can be made to something like the pro systems carb.
After reading this, I believe I am going to just stick with the vacuum secondary. I can always order some quick fuel metering blocks that will allow some additional adjustments that these don't have.
Thank you for all the input!
The secondary tube mod is used on the street avenger because it has trouble opening the secondaries. Specifically on the 770 version. The smaller version does not have this issue. It is essentially enlarging the signal hole from the primaries to the secondary vacuum pod. Holley used to make this a standard feature, but from what I assume is cost savings, they stopped doing it. It helped quite a bit along with tinkering with the secondary spring, though. The secondaries used to open way up in the RPM range, even with the lightest spring.
The guy selling the Pro Systems carb has the spec sheet. Based off of it, it would be a decent fit for my set up, but would still need some tinkering.
The street avenger does not have replaceable air bleeds but I am in the process of changing that. I ordered some blank air bleeds and I am going to drill/tap to install them. I'll at least be able to fine tune it a little more. As of now it's tuned pretty well. It doesn't have repalaceable PVCR's, though, which is unfortunate.
I have a vacuum gauge, and a wideband o2 as well. They definitely help with tuning. I'm not so much having a hard time getting it tuned right as I am deciding on whether or not a mechanical secondary is a better fit for this set up in general. I also like the additional adjustments that can be made to something like the pro systems carb.
After reading this, I believe I am going to just stick with the vacuum secondary. I can always order some quick fuel metering blocks that will allow some additional adjustments that these don't have.
Thank you for all the input!