New headers TTI or Doug

AdamR said
Dyno it, I bet you will be surprised. Im not trying to put down your combo but I bet its much closer to 425 at the crank then 480.

My old 340 made 480 at the crank, 11:1 compression, race gas, heads flowed about what your do, Huge solid cam 265@50" , Victor intake, 750hp carb. 483hp at 7000rpms, 410ftlbs of torque at 5500rpms. It was enough power to push a 69 Satellite in to the mid 11s, so even if you are only making 425 at the crank you should be able to get your 11.80s

still how is a 318 in mopar magazine making 400 and mine would only make 425?

Package eight:
360 rebuilt with 9.5 to 1 cast pistons, original crank, rods and windage tray. 202 heads with competition valve job and ported to flow 260 cfm. Edelbrock RPM intake, Holley 750 rejetted, Large tube headers and Mopar Performance P4120231 cam with .484" lift, 284 duration, 108 lsa, installed at 106 intake centerline.
460 h.p. @6000 rpm
486 lbs. of torque @ 4,250 rpm

Package nine:
360 rebuilt with 10:1 compression flat top cast pistons, original crank turned .010"/.010", rebuilt factory rods. Factory windage tray installed. 2.02" heads with competition valve job and ported to flow 260 cfm. Edelbrock RPM intake, port/gasket matched. Holley H.P. 750 (.076" front, .080" rear jets). Large 1 3/4" primary tube headers. Comp Cams 305AH-8 camshaft with .525"/.540" lift and 305/312 degree advertised duration, 253/260 degrees @ .050", 110 lsa, installed at 108 intake centerline. This motor is a brute for a street car and would only be considered a weekend blaster.
495 h.p. @ 6,000 rpm
500 lbs. of torque @ 4,500 rpm