Hey guys, I am thinking of swapping the heads on my 409 right now I have the following: DART SHP 400 Short Block Kit -Bore Block to 4.165 Eagle Assembly 409CID 10.9:1 Bore 4.165 -Crank 4340 Forged Steel Crankshaft - 3.750 -Rods 4340 steel 6.000 inch H-Beam -Mahle Forged 4032 .040 -5cc -Plasma-moly file fit ring set -ACL/Clevite77 or King rod and main bearing set -Compression 66cc = 10.79:1 Edlebrock Pro-Jection EFI kit Edelbrock RPM Aluminum Heads (Original 6089) Scorpion Roller Rockers 1.6 7/16 studs Cometic MLS Head Gasket .040 Comp Cams Custom Hydraulic Roller Cam Based -08-433-8 XR288HR ground on 112 Center Line I port and polished my heads and Victor Jr. manifold and I have about 178cc ports on the intake. When I run the chassis dyno I am at 433 at the wheels and over 400lbs from 3200 to 6000rpm. I know the heads are a restriction because when I built the motor I had the original injectors in the car 24lbs and had to add about 20% of fuel to all grids ... I then upgrade to 45lbs injectors and during the tuning I had to cut about 20~30% fuel in all the grids to get it to run. Now I am running 34lbs injectors and still have to remove fuel around 10% at 6 & 7k so this means I do not have enough air to support my engine. I am guessing this is like a big restrictor plate similar to what NASCAR does. Here is my engine's numbers: I am thinking something in the 220~230 range. My car weighs 3995 with me in it.