Should I buy this car advise

[Bru]

Unless the person is a reputable mechanic with experience on 7M engines, tear the engine down and check every thing yourself against the service manual or have a qualified Toyota mechanic with the proper measurement tools do it. Find a good local machine shop if you need one.

Things to be aware of:
Check the thickness of the head and the block(from the crankshaft bearing saddle to the deck) and compare to the specifications. Toyota allows 0.010" total removed from stock before having to replace it with a shim gasket or a thicker head gasket to get back to stock dimensions, especially with a turbo. You may have to repair some of the exhaust studs with Helicoils. If any of the camshaft caps bolts strip at 14 ft. pounds then the head has been overheated and the metal is soft. Find another head that is in proper condition.

Torque stock head bolts to 72 ft. lbs. unless you're using ARP studs/ nuts then you can go to 90 ft. lbs. I have used a 0.020" shim gasket (silver seal) under a standard head gasket with ARP studs/nuts torqued to 90 pounds with good results. Some people prefer a metal head gaskets but you really have to have polished flat surfaces to do that.

Other things worth checking are
Oil Clearances using plastigauge. (The crankshaft surfaces may need to be polished)
Cylinder bore diameter and taper. (along with piston diameter and oil Clarence difference)
Compression ring end gaps.
Valve lash on the intake and exhaust camshafts.
Piston wrist pin to connecting rod oil clearance.
Torque everything to specification except the head bolts and use ARP torque lubricant and Permatex assembly lube.
Follow the factory manual to set the engine timing with the timing belt and installation of the cam position sensor or distributor.
Where ever copper crush washers are used: the fuel system, turbo oil connection, get new ones from the Toyota dealership. It's a bitch but every time you tighten them down they get harder and seal less easily.
You can check for a fuel leaks without starting the engine by jumpering the fuel pump in the diagnostic block with the key on. (see the service manual)
I have had good results with Permatex Black Ultra silicone for sealing oil pans, water pump housings, the coolant bypass pipe around the block, valve covers, ect.

When you do the work yourself you know what you've got and where the problems are.