do i have to drain engine block to change header gaskets on 73 318

[texas charger 73]

i have a blown header gasket.. fixing to change,but i have heard they two end bolts go into water jacket. true? do i need to drain engine to change gaskets?

[68 RT]

On a big block you do, not sure about small block.

[Dino]

Yes but you don't have to drain all of it although a coolant change is never a bad thing.  When you reinstall the header bolts put a dab of Permatex ultra copper on them to seal the water jackets.

[A383Wing]

there should be studs on the front and rear, not bolts

[texas charger 73]

There studs were removed by previous builder I assume.

[A383Wing]

put studs back in with thread sealant, then use nuts and washers to hold headers back on in the 4 end holes