This might be an odd question but can anyone tell me if an 883 top end will fit on a Street 500 or 750?  I have the parts left over from my 2010 Iron and was wondering if I could use them to upgrade a Street 500?

No and no .

Just think about it for a moment.......

Thanks R2D2. I thought that was the case but just wanted to check. 

Both are air cooled and yours was.....

LOL and dont forget duct tape

And zip ties...