I have a 73' F250 Camper Special with a C6 auto and a Q-code
428 from a 66' LTD. Right now it has an Autolite 4100 on a cast
iron manifold and exhaust manifolds, and I am looking for a little
more low-end power to get the camper up the Colorado mountains.
I have a Streetmaster 390 manifold and a 600 Holley (from a 75'
F250/390). I plan to pull the heads for a valve job when I install
the Streetmaster, and add a set of headers at the same time.
My questions are:
1. Is the power difference between Tri-Y and equal length headers
that significant at low RPM? I am vacillating between Stan's Tri-Y's
and the Hedman Elites for a couple hundred less.
2. Is it worth worrying about changing the cam for the mild intake &
exhaust upgrade I'm doing? I know that a larger cubic inch engine will
be less finicky about more lift as long as the duration and overlap
aren't too extreme.
Thanks in advance for any guidance and/or experience you can offer.