Actually, you didn't confuse me at all, I think you just didn't understand my question. So let me re-phrase it. You said "use THE turbo on it" which would indicate that you already have a turbo. I asked if the turbo was still on the car and if so "is it for a 302 engine?" I asked that because you never specified whether there was a 351W block or a 302 block IN THE CAR itself. I asked my question because I am pretty sure that a turbo system for a 302 won't direct fit on a 351 block which IMO would dictate whether to stay turbo or not. Now maybe you can clarify a few things about the car or the turbo system you're using. Either way, like I said, fitment would be the only reason I wouldn't use the turbo. Either way, good luck...
To avoid further misunderstanding here is a copy/paste of your original post: "Doing a 408 and trying to decide if i do a all motor high compression (maybe bottle) or keep and use the turbo on it? Will be a good fun street terror and occational strip use. Also i have a block thats 40 over,is it safe or recomended to sleeve it to take it down to a 30 over block? peace"