[StanJ]

Thanks, Curt C. Even though this is our 18th year in business, you’ve caught me “between” website hosting services. My company, Stallion Racing Components, maintained a small template-based site through Quickbooks for several years but they recently sold off their web-hosting service to Verizon…who immediately tripled the monthly rate with no product or service improvements that I could tell. The folks at GraphX are putting together a custom site for us now; I’ll post a link when it’s up…but in the meantime I’ll try to post some pics here tomorrow of the parts I mentioned.

Excalibur, you’re definitely headed in the right direction with a change to the vac. secondary 600’s. The #4224 660 cfm center-squirter carbs are some of the most un-streetable carburetors Holley ever produced (second only to their #4543 850-cfm brethren in that department) due in equal parts to their 1-to-1 secondary linkage and their use of a single 50 cc accelerator pump which – as the name implies – discharges from the carb center into all four venturi at once. Even in the exact application for which they were originally designed (high RPM drag racing small blocks using dual carbs and a tunnel ram) the 660’s never really ended up being the optimum set-up, since the “lowly” #4777 650 cfm double-pumper was functionally identical with regard to airflow (same venturi diameter/shape, same booster design, same throttle body size) once the choke tower was milled away, and was much more flexible with regard to tuning. Granted, the 650 double pumpers are a bit longer due to the presence of a secondary metering block rather than the 660’s in-bowl metering “plate” and because of that you can’t mount a pair of 650’s inline on most low-profile dual-quad manifolds, but the drag guys had been mounting their carbs sideways since long before the 660’s were introduced anyway.

If I could offer a couple of suggestions though, consider plumbing a small (-3 is fine) line connecting the vacuum pods together in your 600’s, and also consider installing metering plates that utilize regular Holley jets and changeable idle feed orifices. These plates are available from several companies (including us) and offer improved main circuit fuel emulsification and – more importantly to you -- the ability to tune for quicker idle circuit response in the secondary…which allows you to use springs of the proper rate (lighter) in the vacuum pods, which you need for dual carb applications if you want to achieve WOT in the secondary venturis. These two upgrades will reward you with much smoother and more consistent throttle response, and likely with a few more top-end horses as well.