Help with tire size
 

I posted this on another site and got no response. Any help would be appreciated.

Hello, FNG here with a 74 C20 Fleetside, lowered 5/7.
I'm so confused trying to search and sort out the info so I'm going to just ask for recommendations.
Thank you in advance for your replies.
What is the widest tire/wheel combo for my set up on 16's without tubbing? I want to keep the stock look of white steelies with DD caps. Coker sells a 16x8 and a 16x10 with 5"back spacing.
Any suggestions on tire size?

Re: Help with tire size
 

Your questions will be difficult to answer without lots of measurements.

https://youtu.be/jkQFUH_dvnI

Good Luck!

Re: Help with tire size
 

First..... How are you achieving the 5/7 drop? The parts combo can & sometimes does guide the options.

16x8 fronts should work but will need things verified to be 100%. I know lots of guys running C10's w/8" fronts using 4"BS. Your C20 has larger rotor/caliper arrangement so you'll need to see if things still clear @ the a-arm lip. It's easier to do 7's if clearance is an issue. With the 5/7 drop you stated, your clearance issue will most likely be the tire height up front. A 225/70-16 would be approx 28.5" up front & even there I'm betting you'd get some buzzing on the top of the inner wheel well housing. A 235/65-16 would be 28" or a 235/60-16 @ 27". Back-spacing & wheel width are key items here.

16x10 rear's would be no problem & won't need tubs. The 10" rears can used 5-5.5" back spacing & still clear the body. My preference is 5" back spacing. The rear height isn't an issue body wise w/the right back-spacing but 16" tire sizes are limited on widths these days. A 285/65-16 would be around 30" tall, fill the wheel well opening, & work well on a 10" wide rim.

Trying to find one tire brand in both sizes (whatever sizes you choose) will prob be a challenge. BFG used to offer a 275/60-16 in the Silvertown classic series by Coker tire but it's no longer made. They look SWEET on a 10" wheel & weren't crazy tall @ 29" so you'll want something along those lines is my thought.
There's also the aftermarket 'taller' wheel tub option for the fronts so your F/R heights aren't crazy different if you can't find a happy medium in F/R heights.

Re: Help with tire size
 

Just realized something on the rears you'll need to check.... On the C10's, the standard rear drums aren't an issue for the deeper back-spacing & 15" rim. However, the HD brake drums for them won't allow the 15" rim to clear. The 3/4 tons have larger/HD drums so you'll need to verify the 10" wide 16's will clear the larger OD drums. I have 8's on my '99 w/5" of BS & could prob do a little more (maybe 5.5-6") but I don't remember if the drums would clear anything beyond that.

Also my previously mentioned 5-5.5" rear BS dimension is based on a 1/2 ton 12bolt housing width. The 3/4 ton rears might be wider which would require additional BS.

Re: Help with tire size
 

You can buy a tool to measure with. Like this.

https://www.summitracing.com/parts/php-01201

Or make one from some angle iron, ready rod and some nuts.

Re: Help with tire size
 

Or use existing wheels & a tape measure.

Re: Help with tire size
 

Scoti hit the nail on the head there, solid stuff. Rears are a lot easier than fronts but without knowing how you dropped the front we cant be sure. I would assume 3" spindles and 2" springs?

Re: Help with tire size
 

Thanks for the replies.
My current set up is 3" lowered front control arms with 2" springs. Shackle and hanger kit with 3 leafs removed in the back.

Re: Help with tire size
 

I warn you now on the dropped control arms.... I had a buddy total his 65swb w/perfect patina (before the current trend) because the control arm drop pocket made contact w/a manhole cover @ speed. Tweaked the frame to an almost cartoon shape.

He had 15" wheels & shorter sidewalls but be careful all the same.