Suggest the best trains among these in Howrah - New Delhi line via grand chord (Not Rajdhani/Duronto).

Poorva Express via Gaya.
Howrah - Bikaner Weekly Express via Lucknow.
West Bengal Sampark...
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Kranti Express.
Howrah - Barmer Express via Old Delhi.
Netaji Express (Kalka Mail).

One more thing, are without valid ticket/without ticket passengers travel in AC 3/AC 2 tier of these trains over Bihar?

#offtopic
A Very Happy 120th Birthday to one of the greatest sons ever born to our motherland!!!
He was one of the biggest reasons why the English had to quit ruling and had to leave with their tail between their legs......
He inspired his fellow countrymen like no other and his war-cry still rages on :-
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" तुम मुझे खून दो, मे तुम्हे आज़ादी दूंगा ।"
" তোমরা আমায় রক্ত দাও, আমি তোমাদের স্বাধীনতা দেব ।"
Mr Bose your legacy will forever live on.......
जय हिंद ।
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Tagging Gomoh and Kalka mail because these two were instrumental in his famous escapade! His birthplace Cuttack also finds a place here.... Tagging Kolkata as he was raised here! He is an aluminus from " The Scottish Church" in College street if I got that right .Also tagging Dhanbad as he took a car ride from Dhanbad to Gomoh.....The car or rather whatever remains of it is still present !!!
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Thanks to Pran for correcting my mistakes!