What is the maximum lift needed?

Hi,

I have an '85 chevy k10 pickup. What is the maximum lift needed to fit 37 x 12.50 inch tires on a 16 inch wheel with 4.438 inch backspacing and a -27.00mm offset or 38.50 x 14.50 inch tires on a 16 inch wheel with 4.5 inch backspacing and -51mm offset?

I am willing to trim the fenders.

Thanks  

I'm running 38.5 14.50 16.5 with 4.5" back spacing on my 83 Chevy with 7" of total lift and some mild front fender trimming

that's with the 76 front clip that was on it trimmed to match the high clearnace bumper I built

this is with the 85 front clip with some fender mods  
if it ain't dirty, you ain't doing it rite, RNC club motto

Wow! That looks great!

My truck currently has a 6 inch suspension lift. I have measured from the center of the knuckle and it looks like I can fit those tires with mild modification to the front of the front fenders.

Do you have any tips for measuring to make sure that I can fit those tires without it rubbing against anything else?

Also does trimming the fender in such a way compromise the integrity of the strength of the fender (ie. will is flop in the breeze?).

Thanks  

the way I trimmed the fender I started with a rust free fender measured and marked on the old fender then layed it out on the new fender and trimmed, I also added sheetmetal back in to fill the void left by the trimming, on a side note I raised the front lower edge of the fender 4 1/2" on the 80's body fenders to avoid rubbing and match up to my high-clearance bumper (also shaved and filled where the side marker belongs but this is not necessary I just wanted to do it.)
as for the flopping in the wind, the ones on the old front clip did not, the issue I was incountering is that Iowa winters are not nice to steel and the whole fender lip had rusted away, so my suggestion for you is to start with a decent to exelant set of fenders and anywhere you remove metal spot something in to fill the void left.  I will take a couple more pics of my front fenders for you so you can see what I did, but these are just ideas, sugestions, and my own opinion  
if it ain't dirty, you ain't doing it rite, RNC club motto