28:1 has 30% less fuel than 40:1.
My jetting with the following mods at sea level were:
91 octane mixed 40:1 w/YamaLube 2R
T5's
stk bore/stk port/stk head
Chariot billet reed cages w/2stage boyesen reeds
Chariot billet non cross-over intakes
Stk bored carbs
K&N pods w/outerwears
+4* timing
27.5 pilots
stk needles w/needle clip in the middle groove
310 mains
A true plug chop is done going through all 6 gears WFO, pull in the clutch, kill motor, stop safely, remove and replace plugs to be chopped.