Hello! I’m 14, and have been working on and riding an 85 350x. I typically work on it with my grandfather, he’s really good at machining and engine repair etc. But anyways, a couple years ago we made the completely wrong decision with my 350x head and reamed out one of the valve guide holes (where the valve guide drops into the head). We didn’t even think about freezing the valve guide to get it to fit, I know that it was a dumb decision. Well, since then it hasn’t been an issue until it started leaking oil REALLY bad. Nevertheless, since this is just a project bike I really don’t want to spend $400+ on a head that could be in worse condition than the one I have. I really only have a few options that I can think of, if you guys have more PLEASE REPLY. Option #1, find an valve guide that is 5 thousandths oversized or make one. If you know anyone who makes these, let me know. Option #2, make a sleeve for the valve guide to go into, therefore making it the size it originally was. Option #3, find a better way to glue in the valve guide again. We used loctite last time, and it didn’t hold. Also remember, my valve guide hole is 5 thousandths over, so it would need to take up that space, and be resistant to heat. Please mention any ideas you have regarding that option. I mentioned the possibility of making a valve guide or sleeve, but I need to know the hardness and heat resistance of the original valve guide. I’d imagine they aren’t designed to resist heat, but they are designed to transfer heat. If you have any experience with this or just want to put in your opinion, please reply! It would be greatly appreciated!