There are several core choices..I'd look for a mid 70s from a car or truck..Hear it run first, and bring a mechanical oil pressure gage with you. Aim for under 80K miles, but if it runs nice, and has good oil pressure (over 45psi at 3K, at least 10-15psi at hot idle and no noises) then a higher milage one will work too. I'd expect to pay around $400 for a good one. I would add as new parts: HV oil pump, pickup, pan (if its not a pass engine), cam kit, timing set, thin MP head gaskets, and an air gap intake. That should be about $900 in new parts, add another $70 for gaskets. so, you're up to $1370. A swap meet 750 Holley 3310 or 4150 and a kit for it should end up about $125 more. A curve kit for the distributor and timing tape, $20. Then the flexplate to run your convertor, $80. total= $1595. The "cam kit" is cam, lifters, springs, retainers, and locks for $450 because the 360s may have valve rotators that have to go. Cam choice depends on what the core has for compression and piston to valve clearance with factory pistons. I would also swap out the 8"stall convertor you have, and drop the gears to 3.91s to keep the trap RPM down.
