Fitting a 305/50R20?

I am fixing to purchase a Supreme Suspensions 3 in front and 2 rear block lift. I was wondering if a 305 50r20 with -24 offset has a lot of trimming. If it has a lot of trimming what size tire with 20 in rim should I go with?

Also,
Include y’all mpg with 3 in lift and 20in rims.
Thanks

 

Tire calculator to figure your gearing impacts.

Is this build for a pavement princess?

 

90% it is on pavement

 

Wow, I saw that 305 and immediately thought of tractor tires... but turns out that the 50% sidewall profile still keeps it moderately short, at only 32 inch diameter.
On the back, you could throw them straight on no lift no trimming, and call it a day.
I can't really say much about the front though, because wide+offset can amplify clearance problems.
I think that people go up to 265/75R16 with factory rims and no trimming. Compared to those, your difference is mainly width+offset, as you're adding 1.5 inch to the tread width. But you're going up 3 inches in the front, so my gut tells me that maybe you can get by without trimming, or just a little bit of plastic.

EDIT: Do you know what the truck will *look* like with 3" lift and only marginally bigger wheels?

 

Don't have a lift, but I do have that size in the rear. I don't remember the offset, but I have 50mm spacers anyway. Just to make things look stanced or something. 275/55/20 in the front.

Fuel economy on the highway if I stick to the speed limit and always gently accelerate is around 20mpg. Fuel economy in the city with a mix of driving is probably 12mpg. Fuel economy when I want to feel like I'm racing, is asymptotically approaching 0mpg.

 

What is the width of the wheel, that makes a big difference? I just put on 17x8.5 -10 with 305/65 tires and with the mud flaps removed and fender flares trimmed, it doesn't rub in daily driving. But your -24 offset will put the wheel out a bit farther unless it's something narrow like 7.5 or less. Here's mine with 17x8.5 -10 offset with 305's.If I had -15 or more, I'm sure it would rub pretty bad. I also have a 3" lift though.