Need help deciding on a new cam

If you go any more than what you have now, chances are you'll start pulling the studs out of the stock heads, unless they've been changed to screw in type studs. If you really do want a more radical cam, it's best to wait and do the cam swap along with the heads. The AFR heads will be able to handle just about any cam profile as is. It would also be advantageous to check the piston to deck height (clearance) when doing the head swap, and then making a cam choice then after figuring the actual compression ratio with the new heads. Not all flat topped 302 pistons are equal, the pin height (compression height) varies from 1.585 to 1.615, that .030" difference can change the ratio by a half point or more. So if you had 1.585 pistons and went with a 64 cc head, your actual ratio could be less than 9 to 1 vs a 10 to 1 ratio with 58 cc heads and a zero deck piston (1.615)

i agree with DH. get the new heads first. then decide on a new cam. the heads will give you about 40hp over the stock ones out of the box, and you may decide that is enough. if not then i recommend going with a slightly smaller cam than the isky 280 megacam. the 270h magnum cam from comp cams would be a better choice imo. and as for heads, i recommend the arf 185's over the 165's.