Mike - it sounds like you're right in the wheel house..........
and realistically no changes need to be made , a few notes worth comparing
Carburation - you nailed it
, many arguments over 600 / 650 vs 750 , for applications 600s always win and run best
4800+ rpm - are you running out of prop (?)- you are most likely exceeding the prop's efficiency
changing pitch will not do much - changing TYPE from old school sand cast to new style CNC (Acme)
will make a difference - however the cost of experimentation can be prohibitive.
3 blade acme has comparable blade surface as 4 blade sand cast - and is MUCH more efficient
Ignition - personally I like to base line the timing at several different rpm, full advance should be in somewhere
around 3k being mechanical advance you check that on the trailer or @ the dock / NOT MOVING ......
HEI is a fantastic choice (though a marine unit like DUI is a better choice)
(full amount of total advance the distributor moves + your base timing should = your total advance).......... and that's where
it can tricky hehehe
Again and as you already know any changes to the above will yield small incremental if any gain, or worse create a catastrophic failure.
if it starts easy - and runs smooth up to WOT - you're pretty much done .............
no more typing on this subject - call me and or Eddie , anymore info and someone will surely blow something up
Dan T
