Combining 4 days sighseeing by myself with a busines trip.

Arrive Delhi Mar 31 8:30 pm from USA and need be in Mumbai late evening Apr 4.

Potential Itinerary:
Date Depart Arrive
Arrive Delhi Mar 31 8:30 PM
Delhi -> Udaipur Apr 1 1:05 PM 3:10 PM
Udaipur Apr 2
Udaipur -> Jaipur Apr 3 2:00 PM 3:00 PM
Jaipur -> Mumbai Apr 4 9:10 PM 10:45 PM

Or is it better to spend 1 night Udaipur and 2 nights Jaipur?

Regards

Don't know if you've ever been to India before but if it were me, I'd skip Jaipur altogether and instead do a day trip from Udaipur to take in some of rural Rajasthan, visiting the Kumbhelgarh Fort and Ranakpur Jain Temple. The City Palace complex (including the Crystal Gallery) at Udaipur will consume the greater part of your day and possibly more than that if you want to include the boat ride on Lake Pichhola to the Jag Mandir lake palace. There is a City Palace in Jaipur but it pales in comparison to this one. Better to take in this great Indian city on its own than to rush through two cities that are kind of similar in many ways and avoid the hassles of additional flying in India as well.

Same advice as Craig. Go to Udaipur and enjoy the city and surrounding area. I've spent about 8 days there and never ran out of interesting things to do.

Or split your time between Delhi and Jaipur.

Would this make sense:

Mar 31 Arrive Delhi 8:30 PM
Apr 1 Delhi: Red Fort, 1-2 other sites, Sound/Light Show
Apr 2 Delhi-Udaipur flight 11:40 AM - 1:30 PM
Apr 3 Kumbhelgarh Fort & Ranakpur Jain Temple
Apr 4 Udaipur: City Palace, Jag Mandir lake palace
Udaipur-Mumbai flight 7:25-9:15 pm

You might want to take in some sights in the City Palace complex on your first afternoon in Udaipur.

My favorite sight in Delhi is Humayan's Tomb which is not in the area of the Red Fort, although the nearby Jami Masjid mosque, Chandni Chowk and Raj Ghat are interesting. You can probably do all of these in a day.

Otherwise your itinerary works.

I agree -- just got back from an India trip and if doing it again, I'd skip Jaipur.