#'s Matching 340 build

on stock exhaust
as backpressure rises it handicaps high rpm hp
so my goal was to max out the flow at the lowest and over the broadest rpm as possible
some use pressure demand
what you don't want is backflow of exhaust into the intake , as well as purging the most residual ex possible
so you have to watch the valve job and backcut along with the exaust close (early) and intake (late)
I usually say to minimise ooverlap but that's simpistic
lucky with the long rod opening the intake early to try and track piston demand is not as tough a it is with popular short rod engines
npt only do you have more degrss- dwell- around tdc but the max piston velocity is several degrees later
othing is for you advance the cam an additional 4 degrees to affect Intake close and dynamic compression is that you FUBAR overlap valve events
(that's IF if the big camgrinder did in the first place- not likely if the specs are exactly the same as for a sbc)
quite different than headers open or mufflers