How much value would I add if

[69Z28-RS]

If you plan to have the car 'judged' in original class judging, putting the top on would add 'points'....  otherwise, I'd leave it alone as is unless you WANT the top on it.  If 'original judging' is how you have fun, then the top should probably be put back on, but the real answer to your question is 'what is FUN to you'? 

PS>  I traded for an orange/black Z28/RS back in '75 or 76, and my original plan was to *restore* it without the vinyl top ( because back then, my logic was:   vinyl tops add weight, hold water, allow metal to rust from underneath, etc'!   Now, after the car sitting in my garage for 30 yrs (undriven), I've decided to keep it as 'original as possible', even plan to finish cleaning and show it (hopefully) in the original unrestored class at the nationals. 

Gary / 69Z28-RS

[lcmc]

OK......we'll put this to rest. I got the car delivered today. Took it to a high end body shop and between him and I we decided best option was to wait until car needs repainted then put it on. Looks like that may be awhile since it was last painted 27 years ago and the paint is amazing for its age. Thanks for all your responses.

[KurtS]

Good choice.
Me, I'd probably never add a top to a car that has the studs ground off. Especially a done car.

Value-wise. I dislike tops enough that I'd be happy if the top wasn't on it. Even a very nice over-the-top resto. It's one of the very few things I'd accept being non-original.

[BillOhio]

I have rode with Danny, he will see whats under the hood

[plumL78]

You know that you will have to re paint the filler panel and stripes because they are in a different position on vinyl top cars

[IZRSSS]

I dislike tops enough that I'd be happy if the top wasn't on it.

OUCH...

[lcmc]

You know that you will have to re paint the filler panel and stripes because they are in a different position on vinyl top cars

Yes