69 Barracuda race car

Actually they're so abundant now in the aftermarket their reasonable. Nothing of mopar will ever be as inexpensive as a smallblock Chevy but you're starting off better. Look in the 10 second builds I think you'll find many standard stroke 440s,
Your goal of 7 seconds shouldn't be hard to achieve. I imagine the car is geared well, maybe get the converter rebuilt or replaced.
Did the previous owner leave you a build sheet or anything ?
The previous owner died about 15 years ago and his wife knew nothing and had no paperwork whatsoever