Ok, I'm about to buy two tickets to Rio (GAG).

I sure hope you mean GIG.

to JFK. But then I would depart LGA for IND. I would arrive in JFK at
6:05am and depart LGA at 4PM the same day. My question is: would that give
me enough time to get to LGA?

That's ten hours. You could walk from JFK to LGA in half that time.

The NYC Airporter bus runs about every half hour, takes half an hour
if there's no traffic, an hour with traffic, fare is $13 if you buy a
ticket ahead of time on their web site:

http://www.nycairporter.com/OurServi...Transfers.aspx

If you don't have more luggage than you can carry, the transfer by
public transportation is easy. Take the JFK Airtrain to Jamaica, buy
a $7.50 Metrocard at the exit, use it to exit the Airtrain ($5) into
the train station. Follow the signs to go downstaits to the subway
station, and use the same Metrocard to enter the subway ($2.50). Take
the inbound E train five stops to Roosevelt avenue, go upstairs to the
bus stop and take the Q70 bus (free transfer using the Metrocard) to
LGA.

Either way, even if JFK customs is slow, you will probably be at LGA
before 10:00 AM. Delta has flights to IND at 10:00 and 12:56, so if
you ask nicely and perhaps pay a small change fee, you can get an
earlier flight.

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John Levine, , Primary Perpetrator of "The Internet for Dummies",
Please consider the environment before reading this e-mail. http://jl.ly