Any oil will do, but if it were my car, with that many miles, I would just keep using whatever you're using now. The Royal Purple is a pure synthetic, but it's extremely expensive @ $7.50/quart, what you're using is definitely good enough.
I recommend saving ahead of time for students or young people in general, it's usually much harder to come up with the necessary funds. Although, it really depends how important the car is, is it worth the money, do you have debts already, if you had to, would you get a loan to do it, or do you have plenty of money, and it's really not an issue, ya know. As for the engine, it's really a matter of preference. Some people swear by a rebuilt engine, some swear by a new one, whether from a lower-end company for cheap, 2-2.5k, or a really good one, or even a brand new Ford motor. Myself, I've had two engines rebuilt by hand, and one brand new, and I definitely prefer a hand built engine. But honestly, I would ask around, especially here at Stangnet, and get a lot of opinions and advice, and try to make a good decision based on what you think is best. Rebuilding or replacing an engine is never cheap, and you definitely need a trusty mechanic, for anything ya can't handle yourself. It took me about 2 years to find a really good mechanic, it's nice to have someone you can trust, ya can't put a price on that, I learned the hard way. GL
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