5.9 Magnum exhaust/intake combo help

Whatever you do, upgrade the valve springs.

The springs in it are for low-redline (my 5.2 Dakota is something like 5200 rpm iirc) and the motor had a nice fuel cutoff rev limiter before the efi was removed.

Without the efi and with better intake exhaust, it will easily outrun the oem valve springs. This is why my dart is crippled right now!