Yes! I'm kinda 'hung up' on the intake manifold. Since it will be only flowing air in my application, I'm leaning towards the Victor 383. It flows plenty of air and will make great H.P. The Eddies RPM 440 is a nice choice but I think it will be a 'restriction' at 4000 on up with 500" especially a big bore ,(4.375), nice stroke,(4.150), short lightweight piston,(1.220), so it should rev very quick and it will need a good induction to make higher RPM power. I really wish INDY would make a low deck 400/383-3 dual plane. That 440 dual plane they have can outflow the Victor series according to published data from AR Engineering.(Jan 2007 pp. 22). It was a very good and scientifically done article about intake flow through the manifold only. It shouldnt be used as an absolute guide due to the abscence of firing pulses the engine sees while running but it does establish a baseline for intake flow development and was very interesting and eye opening! Especially the fact that their dual plane can outflow the Victor 440!