Purple Vs Lunati Voodoo

G'day & Welcome to FABO

Tell about how to build a throttle/kickdown linkage bracket for a /6 Aussiespeed Hurricane and I'll tell you what I know about the '73 318. (lol) I'll start.

Compression ratio is 8.6:1 at best on a USA spec '73 318. With that compression ratio, I don't recommend anything over 214º duration @ .050 lift. Mill the head about .020, do a 3-angle valve job and use the 67-70 318 piston, you can get away with up to 224º duration @ .050. That ought to bump compression to around 9.3:1. Going much past that with iron heads is tempting pre-ignition with the fuels in the US. Stock heads tend to quit gaining flow around 5500 rpm.

I built a 318 using the P4452761 cam (268/272 .450/.455 lift) and P4120249 springs. I used a 625 cfm Carter and a dual plane Eddy. It was a fun, responsive street engine. The springs will support up to 284/284 .484 lift cam.

Mopar Performance makes hydraulic cams up to 320/320 .533 lift for fully modified drag engines. I've heard good things about the 292/292 .508 lift cam in the 360. IMO it's too much for the street.

I don't have a Lunati/Holley book, so I don't have anything from there I could recommend. People seem happy with the Voodoo line of cams they make.