With my latest engine build I almost went with a 460 based motor because the block and some of the FE parts are real expensive. But after much thought and research I again went with anothrr FE. If you stay with apx 500 HP or less, a 390 stroker like the 445ci can be built for around $7,000 (+/-).
I was able to buy a built 428 with 525-550 HP from a well known FE engine builder for $6,500. Deals can be found.
If the 385 series will fit under the Hurricane hood like the Surperformance, a fairly stock stock engine with 450 - 500 HP can run around $6,000. 600-700 HP for $11,000, 800 HP for $13,000.
Don't worry about people here and elswhere about the noise of Cobra's with loud exhaust, the 427's were built to be loud. If someone want's a very quiet Cobra , build a under car exhaust, if not, don't have a 427 Cobra. Buy a Cadillac with 4 mufflers and be happy.
Also, don't let a few rude members here piss you off or turn you away from this wonderful forum, there's always a few in every crowd.