Tire and wheel size

[Budweis]

well i finally decided im going to give up on finding drums for my 70 c20 3/4 ton and convert it over to disc . i figured while im at it im going to add a 4" lift and some new wheels and mudders. my question is do i go with 15" wheels or 16" or 16.5" like i currently have? and what depth of rims? i was thinking 10" as i wanted some pretty meaty tires.but i also dont want rub problems so i figured id get some suggestions and also any advice on offsets or if someone has same setup maybe you could recommend some part numbers also does anyone know what size mudders i could fit on my truck with this setup? any suggestions appreciatied. oh yeah also while im at it do i want 52 inch springs for the back or 56 and what are the differences? or 4 inch blocks for the back? sorry for the load of questions but really wanted to start ordering parts and getting on this.

[Dean]

Is this a C20 or a K20??

[smokekiki]

16 or 16.5 will clear the 3/4 ton calipers.16" tires are availible in a lot more styles and sizes now compared to what you were able to get a few years ago.when you air down for serious off roading,a 16" will stay on the rim better than a 16.5 because of the saftey bead.For on road 35" is max for a 4" lift.Off road you will hit.Now you can also get 17",18" and and bigger rims!

[Dan72cst]

I think 68 was the last year on the 56" rear spring. Your 69 should have the 51 inch. Its always better to go with the lifted rear springs, rather than blocks. You could also go with a shackle flip in the rear fo 4 inches of lift and keep the rear springs and no blocks.

[Budweis]

ok thanks for the input and thanks for the spring info dan. i think ive decided to go with 16x10 wheels and was looking at super swamper #SSR-69R 35x14.50R16LT that say the tread width is 12.2 inches. anyone have these tire or can say anything bad about them? should this fit ok i would think they would as i got 33's on it right now and dont even have a lift but off road and turning bit they barely clip front fender. i know they will fit ok on rims just mean clearance wise? i was going to go a little more aggressive on the tire tread but started thinking ill prob still want to drive it on the street a bit. any thoughts or suggestions will be looked into,as i want to do this right the first time. also anyone got any info on the shackle flip thing? as i think thats the route gonna take. thanks

[smokkey1]

go with the 4" shackle flip from ORD and stay with the 16" rims you could also go with 15" rims but you'll have to grind the calipers in the front the backspacing will determin how much you have to grind. I'm running 4" lift with 36x12.50 swampers and don't hit on normal street driving, but it's going to hit when I flex it out. but I'm going to do some trimming to fix that...www.offroaddesign.com

[Destructo]

You'll probably rub some with 35" swampers, swampers run a true 35" size normally and sometimes bigger for their BIAS tires. So maybe going with a 4" suspension and 1" body lift will help you clear them?

[Budweis]

thanks for the link smokey was just what i was looking for! hopefully if i hear from bram this weekend im going to go get my new front diferential assembly the next weekend and take it to get rebuilt. maybe i should just go with 33s as dont want a rub problem and kinda afraid to go more than 4" as it already puts it illegal in missouri, says 24 inches to bottom of bumpers and thats where im at now without lift. it says if truck was classified gvwr 7,501 to 9,000 it could be 30" can a truck like mine be classified with that gvwr? i know they gave me few choices when got licensed first time but i didnt know would affect so chose the 4,500 one. would be nice if could go for 30 one then could have up to 6 " lift. maybe ill give them a call this week and found out.

[Mudder]

your gvrw is on your vin tag. license office or license has nothing to do with lift limits. its the inspectors that check that or (let it go).... you should be in the 28 front and 30 rear range. you have seen my truck here and I have never had a problem. Really you need to find someone with a lifted truck in your area and see where they got it inspected. Talk to others..

[Mudder]

Found this for you beings we are under the same laws when it comes to lifts. You can find this stuff through the State Highway Patrols website.

Maximum front Maximum rear

bumper height bumper height Motor vehicles except commercial motor vehicles ................. 22 inches 22 inches commercial motor vehicles (GVWR) 4,500 lbs and under ...... 24 inches 26 inches 4,501 lbs through 7,500 lbs ................ 27 inches 29 inches 7,501 lbs through 9,000 lbs ................ 28 inches 30 inches

I am a little over.....

[Budweis]

yeah thats same info as in my book but when i went to license burea here they asked me what gvwr plates i wanted like i had choice. unfortunately i told them 4500 ones. to me the law seems pretty lame as my truck is at max height for 4500 plates just being stock. they said my truck passed by 1/4 inch last time took.
yeah i guess ill just have to find a good inspection place like you said.

[Mudder]

The plate you run has nothing to do with the height of your bumpers. Look on your vin tag on the truck. You will see the weight there.

[Budweis]

yeah says 5,200-7,500 just trying to figure out when went for inspection they told me front had to be no more than 24 and rear no more than 26, guess the place was screwed up.

[Budweis]

got another question for you, i think i want a little more than 4" and was thinking bout ordering a 1-2" body lift. question is when installing a 1-2" body lift with a 4" suspension lift will any unexpected things have to be done like with the steering or any modifications that i may be unaware of?

[Budweis]

ok decided to go with a ruff country 6" suspension lift kit and just bought 16x10 wheels. ready to purchase tires now. im going with super swampers i think, i was looking at a 35" x 14.50" question is will 14.50 be ok for clearance with a 6 " lift. most of the tires i like either dont come in 12.50 width or they only made for 16.5 rims. lol guess i should have went for 16.5 but got a bargain on the 16's. i like the idea of a wider tire just wanted to make sure wont have clearance probs before order, my offset on new wheels is 4-1/2 inches. thanks for any replies

[JIMs70GMC]

I don't think you'll have any problems.

[smokkey1]

umm you should look in to the tuff country they ride real soft unlike the ruff country...you might rub with the 14.50's not real sure though but a little triming well fix that... good luck

[Budweis]

sorry made an error there tuff country is one im going for was typo, get mixed up easy with all the names being almost the same lol

[smokkey1]

no problem I do that all the time....BTW good choice you won't be dissapointed......