Head gaskets are bad on my 2008 OBXT and will be replacing them soon along with a new upgraded clutch for future power gains. Motor has 130k on it. I want to, at the very least, get the heads decked. I’ve got three questions for you guys; 1) Should I do anything more machine work than deck the heads? 2) Any suggestions on machine shops? One that could possibly just swap heads with me instead of having to wait for the work to be done? 3) Should I just go OE on the gasket or is there a better option when going for more power? Engine is pushing exhaust gas into the coolant and forcing coolant out into the overflow tank. Temp gauge needle HAS gone up to the top half of the gauge but never into the red. I had the bad head gaskets verified by JP Automotive, so it’s not a water pump issue, radiator cap issue or something else.
You can get a precision straight edge and a feeler gauge to make sure the block didn't warp. If it's in spec you shouldn't need to touch them. If it didn't overheat it is probably fine but it's an easy check if it's out. Heads should be decked every time they come off. It doesn't cost much and it's an easy job. Decking the block is tough because you might need to disassemble the rotating assembly. On that note, it might be worth your time pulling the rotating assembly apart and putting new connecting rod bearings in, and cleaning/checking rings. It's a lot of work but you wouldnt want to figure out the hard way, that the coolant found its way into the oil and dried the bearings out. I did an outback and swapped a long block into it. I did head gaskets while I was at it and I found it knocked on startup. I regret doing all that work without doing bearings but again, it's a lot of work... Maybe someone else can add input.
Sorry I used a lot of words to answer just one question. For number two, I sent my heads up to the machine shop in Rosemount across the street from. Upull. They had it done in a few days. Can't remember their name but they decked the heads for 200ish. For three, I went with wrx multi layer gaskets on an na motor but I think any multi layer should be good.. Logically you would want to do head studs over bolts but I'd you aren't going forged internals, then the stock ones should be fine? That's more of a money saving thought process and some may argue with me. I don't think studs are worth it on a stock rotation assembly.
