You basically need to take the valve cover off and run a feeler gauge between the lifters and cam lobes(w/ a FSM) and check to see if they're w/in spec.

 

I had my head crack on my 96 3rz with only 160k miles. The fatal flaw is the 4 valve design. As mentioned the metal is thin between the valves and is prone to cracking and that is exactly where mine cracked.

I was really screwed due to the fact that my engine has a cap and rotor distributor. I called around and verified that the heads from cap and rotor 3rz ARE different from the heads for a distributorless 3rz. Because you are limited to heads from only the older 3rz engines it really doesn't make any sense to pull a used set of heads that may crack 1 week or 6 months down the line. I ended it going with a brand new Toyota head. It did cost a pretty penny but as I see it the rest of the motor should be solid and ready for another 150k plus (knock on wood).

 

Damn man, that scares me a little bit.

 

well, I saw new aftermarket heads fully assembled with valves, cams, etc... for only $450-ish on eBay. So, my best bet is probably either to go with a used low mileage motor, or pull the block and make sure it is ok, and get one of these heads. Or, find someone parting out a truck/engine and get a used head.

 

man that sounds like a pretty good deal for a fully built head. Do you have a link for the auction(s)? Make sure they're not reground cams, b/c once you lose the baseline on a cam shaft, your power band changes and it's not the best option when it comes to cams. As far as pulling the block, man I'm willing to bet you money that your block is fine. My 96' Tacoma 3RZ oil pump shut down and the pistons scored the cylinder walls, but all the machine shop had to do was bored it .030 over to get it back in shape. You could probably get a machine shop to re-work your block for around $150. Your biggest cost is going to be the cylinder head & rebuild kit.

 

[QUOTE=wslytoy;50886761. If it does break, you'll be fine. The 2RZ, 3RZ, & 5VZ are all non-interfernce engines. Your valves will not make contact w/ the pistons if the chain/belt ever broke in one of these engines.[/QUOTE]

the 3rzfe motor IS AN INTERFERENCE MOTOR