Got a chance to pick up a 1.3 Volvo drive to replace my standard 1.63 Volvo in my 19' Nova. One of the issues I have always had is when you get past a 21 pitch prop your selection is almost nothing. I have a 23P Solas on it now and like said the drive is a 1.63 its about as big as it gets. The only way I can describe it is it (496 roller motor and a Volvo 270 with 280 trim shield) feels heavy with the big prop. Great cruise, strong pull but.... and now that this 1.3 is available its got me thinking (just for prop selection alone).
So here is the question.
What is better and why (characteristics) please;
1, A smaller gear ratio in the drive and larger prop
2, bigger gears in the drive and a smaller prop

diff in ratio is about 20 percent. so your 23 pitch will feel like a 27. you will need a 19 or so to come close to same operating rpm.

Ya, I understand that and is a good reason alone (prop selection) but what other advances or drawbacks would there be?