it'll have a large affect if you don't compensate for the removed blocks.
Have you noticed that the back of the truck drops close to 2" when you load it?
I have the same thing on my old 1500HD, truck sat really high in the back, but was perfectly level when hooked to my trailer.
If you want a levelled truck when unloaded, you'll need to get some airbags to compensate for the weight when loaded. Otherwise your backend will sag 2" when you hook up. CAli style, I believe is what those yungins call it..lol
2014 Ford F-150 XLT, HD Payload, Max Trailer
2010 K-Z Spree 318BHS