[StanJ]

While technically, Pro Systems is a business competitor of ours (although our markets don't actually overlap all that much), the simple fact is that Patrick is on the money with his recommendation here. Holley's marketing department is far more responsible for the #80496 HP 950's claimed airflow capacity than anyone in their engineering department. It's sad these days just how many fuel system companies prefer to do their product development R&D with a word-processor rather than a flow bench and dyno. The 950 HP carbs share the 1.375" venturi diameter with the 750 cfm family of Holley 4150 series double pumpers (HP and otherwise), differing only in their 1.750" throttle bore diameter as opposed to the 750's 1.6875" TB diameter. In many applications, the 950 HP is in fact slightly more responsive than it's 750 HP sibling due to the main circuit coming online a bit quicker, making the carb less dependent on accelerator pump discharge...the main exception to this being applications that by nature really dependent on transfer slot length.

Anyway, we've also built many, many carburetors for street-driven 400+ cu. in. Windsor applications in the this general power range and when properly prepared and calibrated, the 1.375V/1.750TB "950 HP" platform is by far the best starting point in Holley's product line for these engines.

Stan Justus
Stallion Racing Components