What tires and width in the back of my stepside??

[1974chevystepside]

Hi guys well i finally got her up and running! Magnacharged 355 . any way the back tires are MT Sportsman 29x15x15.5...wide tire..it looks badass.. but are they too wide for the amount of weight in the back??? plus the rubber is 5 years old on those tires. it breaks loose at 40 mph easily! so any recommendations?? i am looking to got with a 30 inch tall tire as it is 4.11 gears with a th700r4...loooow 1st gear! its runs like a scalded ass monkey! Thanks guys!!!

[babyJay]

What weight are you referring to? Just the weight of the empty bed? Some pictures would be nice too.

[1974chevystepside]

thanks for the reply. it is only 2wd and will usually be empty. sorry cant upload pics now...but soon..thanks again..

[1974chevystepside]

ps stock weight with and additional 250lbs...in between the frame in the rear..just in front of the bumper.

[1974chevystepside]

just trying to figure out if this tire that i am currently running is too wide or not. i am wanting to replace the with some good sticky tires. trying to figures out if maybe i should go not quite as wide?? Maybe a 13 or 14 inch wide tire would be better?? Also can you go with too wide of a tire?? thanks again..

[1974chevystepside]

anyone??

[1974chevystepside]

ttttt,,,,,,,,,,,,,,,,,,,,,,,,,,,

[Gemp]

What is your rear suspension set-up? Because if your still bone stock, You might need to start looking there if you really want to hook.... As far as tires,The drag radial market has made leaps in the last 5 years or so.

[1974chevystepside]

i am running the lakewood tracktion bars. with my gearing should i step up to larger tire than a 31in tall tire??

[N2TRUX]

Welcome to the forum 1974chevystepside. I moved your thread to see if you might get the information you want in this forum.

[1974chevystepside]

thank you much!!! is this when i post a pic with a NEWBIE stamp on my forehead!??? lol!! thanks again!

[Super73]

Are you setting this up for drag racing?
What RPM do you spin the motor to?

Those are the first questions to find out proper tire height/gearing.


As far as a tire being too wide to hook against weight, well I have never heard that being an issue unless you are in the mud or snow and need a narrow tire to dig down through the substance finding a hard surface.


I run a 4.56 gear and a 315/60/15 MT ET Drag radial which is a 30" tall tire. But I also spin my motor to 7,200ish.

[1974chevystepside]

thanks for the reply... with my cam i will only be spinning to 6,000 rpm

[Super73]

Assuming 5% slip with your converter, you could do as much as 124mph in 3rd gear at 6,000rpm with a 30" tire and a 4.10 gear.

65mph would be about 2,200 rpm in 4rth (with an unlocked converter with 5% slip). Don't know if the 700's have a lock up, if they doo, than your RPM would be about 2,100 at 65mph.

I'd guess the reason you get so much tire smoke would be due to the tires you are running, suspension setup, the 700R4 having a deep first gear, and you have a blower.

Where does your verter flash (IE what stall speed is it)?

[1974chevystepside]

The converter is only a 2500...and i do have switch to lockup the converter which i would only use on the highway, which that maybe 3 times a year.. i was looking at the Micky Thompson ET Street 31x14.5x15s.. i am running tubes in the current tire right now also.

[Super73]

I had a 30x14.50 ET street before and I like the drag radials a lot better. They seem to hook better both around town and at the track.

[1974chevystepside]

cool...so you are running the drag radial slicks?

[Super73]

This is what I am running: http://www.summitracing.com/parts/MTT-3763R/

This is a DOT legal tire that can be driven on the street with out worry of getting a ticket (well at least until they are down to the wear bars)..

[1974chevystepside]

cool...but you think i should go taller than 30 inche with my gearing?

[Super73]

That is a decision you need to make and here are some questions you need to ask yourself to help you..

What are you ok with spinning the motor to at freeway speeds?
Do you want to optimize the set up for the track?

[1974chevystepside]

i really do want to optimize for the track...as far a freeway speeds..doesnt really matter as it will only be on the freeway a few times a year

[Super73]

What's your truck weigh?

[1974chevystepside]

just a guess...i would say around 4100 lbs

[Super73]

As long as you don't run out of gear you will probably go faster with the shorter tire. The shorter tire should allow you to 60' better due to the over all gearing, given you can hook it at the track (which I'm going to guess with the small converter you have, you will). But it's going to come down to setting the suspension up to work.

What do you have for front and rear suspension?

Get your truck scaled so you know what you are really working with. It would be nice to have both and overall weight and an axle weight so you know what is on the front and what is on the back. That's going to help out a lot with understanding what needs to be done.

[1974chevystepside]

i am running pretty much stock suspension setup with a front swaybar up front except for the 2.5 inch drop spindles... in the rear i am running very soft shocks with lakewood traction bars...i figure i will go with the 30 inch tire. i will try to find a place to weigh it this week..