How huge of a project would this be to remove a vinyl top from a car, and change it to a hard top car? I'm assuming there's sheet metal underneath, but I don't know if there are gaps to be filled and bodywork to be done, or if it's a different cut altogether. Please explain what would be involved. Thank you.

First, you need to remove all the mouldings around the windshield, back glass, roof drip rails, and the moulding that separates the quarter panel from the top. Then, start at a corner and peel off the vinyl itself. Clean off the glue with solvent,and check the top for straightness (Cars that got vinyl tops sometimes got roofs that had small dings in them,because they could be covered with the vinyl). THen you need to remove the spot welded "nails" that hold the rear, lower moulding clips on. Grab them with a vise grips and simply twist them off. The result will be a small imperfection that will need to be filled. There will also be some, maybe 1/4 inch, moulding holes that will need to be welded shut and metal finished. As you may have guessed by now, the top will have to be primed and painted and there is no way you will be able to get by without this. Also, if you are going to re-install the roof drip mouldings, you may find that they are a little bit loose. This is because the mouldings go over the vinyl. You can rectify this by appying a bead of 2-part adhesive under the moulding ,or you can try to locate a set of mouldings that were meant for a car with no vinyl. Good Luck.
Gordon VM
Restoration Motorsports

http://groups.msn.com/Restorationphotos/shoebox.msnw?Page=1

Thanks. I hear there's often a lot of rust under a vinyl top, any tips to deal with that? And how much truth to is there to it and why?

most roofs have extensize damage under the cover unless they were garage kept. The material allowed water to get in and kept it in. I've removed two, both were swiss cheese under the cover. Best you can do is media blast them and fill the pits/holes. Be careful when blasting that you don't warp the roof. Filling and sanding out a roof is a treat all in itself. It took me days to get it close, it is still not perfect but my painter is going to finish touching it up.

I posted a question on sanding roofs (can't remember the exact title line) that MartinSr and Wayne and a couple of the others responded to about 2 3 months ago. A search will turn it up.

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72 Chevelle and a 70 Chevelle with a crushed roof
ACES # 4051 MCC # 448
TC # 1549 81/70 Cruisers