Special to the New York Times

WASHINGTON, March 26--Warfare in East Pakistan would find the regular West Pakistani army with superior numbers of troops and modern weapons, according to United States analysts here.

But they add that the West Pakistanis might nonetheless be hard pressed to put down a determined insurrection, especially if Bengali rebels are joined by the East Pakistan Rifles a 13,000 man paramilitary force, and the 2,000 man East Bengal Regiment, the only Bengali-dominated unit in the Pakistan regular army.

Officials at the Pentagon and State Department said that with the news blackout in East Pakistan, it was difficult to get detailed, trustworthy accounts on the extent of fighting that has reportedly broken out there.

A Pentagon official said that there have been reports, as yet unsubstantiated that the East Pakistan Rifles and the East Bengal Regiment had joined rebels seeking autonomy from the West Pakistan dominated Government.

Reports on Size Vary

The official reacted with skepticism to reports from India that West Pakistani army forces now total 60,000 to 70,000 in East Pakistan. He said the number was probably under 30,000.

Reinforcements by sea would take at least eight days, he noted and only modest numbers of troops could be airlifted on commercial Pakistani air-liners.

Pentagon analysis regard the Pakistan army as first rate in leadership and training. It is armed with relatively modern light infantry weapons from the United States, Britain, West Germany and communist China. But it is believed to have only a small number of tanks and jets in East Pakistan.

The East Bengal Regiment, the first unit recruited from East Pakistan rather than the Punjab region of West Pakistan has only four or five battalions compared to the normal Pakistani regiment of 15 to 20 battalions.

Equipment on a Par

Its equipment and training are considered generally on a par with the rest of the regular forces. However many of its senior officers and non commissioned officers are West Pakistanis.

The East Pakistan rifles are armed wit castoff small arms such as the British Enfield rifles and 2-inch mortars, Pentagon sources say. The Rifles have been trained to perform internal security and border patrol assignments.

Even if the two units fully side with the rebels, a comparison of conventional military strength still would favor the West Pakistanis, Administration analysts say. But they point out there are 75 million Bengalis. If a substantial number of them should rebel it would be difficult for the West Pakistanis to do more than hold Dacca and Perhaps two or three other cities, they believe.

One Administration official said: "If the sentiment of the past several months stands up under fire, the Government of Pakistan will be an occupying force and at best probably will not be tolerated for very long."