Toyota Repair: Engine repair and testing...., blown head gasket, head bolts

Question
I am about to buy a 1987 Toyota Supra 3.0L Turbo, the owner says it only has a blown head gasket. Id like to know two things, to replace the blown head gasket would i have to pull the motor or could i just dissconect the battery cables , throttle body cable, remove the vavle cover remove the head bolts and remove it as one assembly with the engine still in the car? Second is there any tests I could perform to know if the engine block is cracked? pleae let me know A.S.A.P lol ill even pay ya!

Answer
Hello Ray, welcome to my expert page.
There is no need to remove the engine in order to replace the head gasket, you can remove the cylinder head with both the intake and exhaust manifolds attached, I don't know of any test to see if the block is cracked other than a chemical block test but if the head gasket is blown it will show up as a combustion leak no matter what the origin, if the block is cracked let me know because it will be the first one I have ever seen crack in the 25 years I have worked on toyotas.