You're starting at the wrong end of the car.
Chris Alston's Chassisworks, Inc.; Chris Alston's Chassisworks, Inc. - 4-Link (Pro Street)
Listen to Pat, go with a BBC. Juice roller lifters will want to sign off at just over 6K rpm's due to weight, so if R's are limited, you'll want a wheelbarrow full of cubic inches. I'm bettin' Pat can put you a motor together that will make more hp than you can and do it cheaper.