1g 2g swap headbolts bigger?

[BoostinGSX17]

im doing a 1g swap in my 2g and the headbolt on the 1g are bigger but im putting teh 2g head on does anyone know a place or have an idea what i should do becasue the 1g bolts dont fit in the 2g head and the 2 g bolt dont thread into the 1g block

 

[gsx951]

Drill or ream the hole to 1/2"
A drill will work, a reamer is ideal.

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