Ok guys, I just orderd a single mikuni carb kit, BPS crossover exhaust and big blade prop for my 23hp GDSD. Next thing I was wondering is about getting the heads ported and polished. Right now I am running with just me and gear about 21mph top speed. Running a GDSD boat in 16x44. First, how much will the exhaust, carb and new prop make in overall speed? Second, how much more difference will the ported and polished heads make? Thanks.

Dave

PM chops, he should be able to help ya out.

Thery are noticable when tuned right.

Not sure on yer mods - but as to the "big blade" - there were 2 different
versions of the 23 GDSD produced - the early ones had a smaller 10"
2 blade prop - the current ones have the full size 11" 3 blade.....

They have different pulley ratios - the newer ones are 1.7 to 1 reduction
to spin the bigger 3 blade.... You may need to change a pulley to use the
current 3 blade or 12x12 2 blade well.... If in doubt call yer SN in to GD
and they can tell you which version you have....

Just FYI.....