Both studs are broken at the y-pipe.On the pass side.Any ideas that may work without taking off manifold?

 

By far the best way would be to take the manifold off the car. This will allow you better access and more accurate drilling (if it comes to that).

Popular Hot Rodding had an excellent article on removing broken/rusted threaded pieces a couple of months ago. The slickest trick would work on your studs: Drill them for the easy-out (not necessary if you have enough left to grab with a vicegrip), heat up the area and melt parafin (canning wax, available at the grocery store) into the threads. Let it cool, screw the broken pieces out.

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82 Berlinetta, orig V-6 car. Rescued w/86 LG4/TH700R with all harnesses, sensors, ECM, etc. 2.73 unlimited slip. Cat-back from '91 GTA, Accel HEI SuperCoil. AMSOIL syn lubes bumper-to-bumper. Daily driver, work-in-progress (LB9 w/ZZ3 cam, exhaust, paint, etc.).
57 Bel Air, my 1st car. Currently 396 .030 over, Weiand Action+, Edelbrock 1901 Q-Jet, Jacobs Omnipack, 1-3/4" headers, TH400 w/TCI Sat Night Special conv & shift kit, 3.08 10-bolt, AMSOIL syn lubes bumper-to-bumper. Best 15.1 @ 5800' Bandimere. Daily driver while Camaro was being put together.

 

I like to Mig weld an oversize nut to the broken stud, ie a 1/2" nut on the 3/8" stud. Crank the amps way up so the stud gets RED hot. When it cools, it should unscrew easily.