The limiting parts in your case will be the block (80-85 302 blocks are the lightweights of the 302's check your casting numbers before spending any money on the motor, if it's got an E0AE block, it's garbage.), the cam, & valve springs. A roller 5.0 can be turned regularly to 7500 with good valve springs that will control the roller lifters, along with ARP rod bolts on stock C8OE rods. Of course you will also need better heads to let it breathe to get up there.