All I can say is listen to the Steve. He's BTDT. The cheapest performance track motors I've seen are at least 10k by the time your all in. It can be done wisely and watching the wallet, but 2.5k would be tough to do anything but a very basic rebuild.
I'd greatly suggest digging thru the engine section and read what fancies you. There are a lot of ways to skin a Porsche and given the age it's rare want something that hasn't been done already.
Good luck and welcome to the slippery slope (waving from the very bottom
).
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