how much to chop

[dean79339]

I'm going to chop the top on my 77 and am not sure of how much I can take out without giving me headroom problems. I read an article on 73-87 tucks that said they took out 6" I think that will be to much although it looks good. I also would like better details on marking off my cuts. Any help would be great. This is the first step on a long term custom project. I hope to suicide doors/ custom dash/ shave handles/ french in the side marker and tail lights. I have searched but can't find a site that address issues like these. Any suggestions. If I can get a camera I will begin to post pictures as I go along. Thanks