Bare bones, no decking of the head or block required, would run around $40-80 ish for a stock replacement head gasket. Contrary to a lot of what people say (and contrary to a lot of common sense and saving headaches in the long run), it
is possible to do the job with a stock replacement head gasket, all the right tools, a lot of time, and a lot of work. I did it the hard way like this, plus some ARP head bolts, the first time I tore into the engine.
I will never again make the same mistake.
However (
big however), in order to do the stock head gasket replacement, you might also want to get:
1. Top end gasket kit (better yet, whole engine rebuilt gasket kit, HG included) ~ $120
2. New head bolts or studs (studs hold better than bolts, ARP sells them) ~ $180
3. Miscellaneous hardware that you will need to replace ~ $20
4. Random hoses that need to be replaced ~ $50
5. Specialty tools required for the job (torque wrench being a biggie) ~ $50
Total: around $420 (I'd put it at $500 to be safe). You could also get away with ARP head
bolts instead of studs to save money, but I'd stick with the studs.
The list above is completely fine if you plan on strictly keeping it stock. You will basically be back to the engine before it blew the head gasket plus a little guarantee against future blows. However, you will still have all the problems of a 170k mile turbo engine (replacing the head gasket does not freshen up the health of the entire engine
).
If you are more serious about your reliability and room for larger, future modifications, then you will want to get:
(on top of the list above)
6. Metal head gasket ~ $180 and up
7. Required head resurfacing and block decking for metal head gasket. $$$ and up due to the fact that you need to remove the block from the car. If you are removing the block from the car, it would be a highly wise choice to rebuild it as well.
So the options as I would see it are 1.) replace the head gasket with stock type, add in a little reliability to specifically the head and spend about $500, or 2.) go with a full rebuild with a metal head gasket for the most reliability you can get for $1500-2500
plus (sometimes a big plus).
Also, if you aren't doing the head gasket job yourself, expect to pay no less than $1000 out the door.
Some people might try to tell you that you can do the metal head gasket without pulling and decking the block, by using spray on stuff, etc. etc. This is where you will be getting into a debated controversial topic.
Bottom line: go into the deal by assuming the engine has it's pistons laying in the oil pan, and the rods are in your intake manifold - completely screwed.
$500 is a good deal for a supra that has a nice clean body and a blown engine (
if you have worked on them before and are experienced enough to do a complete rebuild on your own).
[thread was moved when I was posting this, might seem kinda out of order]