The Stovebolt Site Forums The Parking Lot Tons 'o Fun Tall skinny tires and 16" or 17" wheel source

Hi 1 ton folks

Trying to get Howard Knapp to run faster without spending $3000.00 for an over drive or finding a decent (now vintage) S10 transmission that is 5 speed to make this old truck run down the road faster than it's current top speed of 53 mph. Currently running 235/75/15's that are supposed to be 29" tall but actually more like 28.5" tall.

I think I need taller tires, it has been suggested that 16" or 17" wheels and tires might be of help.

So who has the secret source for decent 6 lug 16" or 17" Chevy steel or aluminum wheels and then some tall skinny tires?

I have a CPP disc brake kit on the front axle and a 4.10 geared 1985 Chevy K5 Blazer rear end taking up the rear.

Any insight would be a wonderful thing.

MikeC

Patrick's has a conversion kit for less than $300 that will work with your current transmission, engine and rear end. You use this kits to change out the gears in the rear end. I have read this is a simple task for a shade tree mechanic. I have not tried it yet. This kit is suppose to get you about 65 MPH.

http://www.patricksantiquecars.com/chevy-gmc-auto-parts.html#chevy7

From the web site
*CRUISE AT 65 MPH WITHOUT ENGINE STRAIN!
*INCREASES SPEED 15% FOR GIVEN RPM!
*FITS STOCK DRIVELINE
*OPTIONAL INSTALLATION KIT (SHOWN) ALLOWS COMPLETE RESTORATION OF REAREND

Dave, Mike has a 1-ton with a non-stock rear end in it.

I would have thought that a 4.10 rear end would get you over 60 mph. I have a stock drivetrain (216, 4-spd, 5.14 rear) and new 31" tires on 17s, but I've only braved the speedo up to 48 mph in town. There are online calculators that can estimate top speed with some basic info, like final drive ratio (max rpm, gear ratio, etc.) and tire size.

I worry about skinny tires at higher speeds (>60 mph), that's why I invested in wider tires. Handling is great! Tire size can also have an impact on power at the wheels, but I don't think your trying to get to 60 in under 4 seconds!

I have put larger tyres on my '40 , so I can carry the camper ok .

I have had the 15" rim turned off the artillery center and a 16"x7" rim welded on . I now have 245/75 16 E load range.

These seem to measure 30" dia.

I wanted to retain my hub caps , so this has been successful.

edit , I have changed the diff for a '56 unit 3.9:1 and with these tyres , 60mph is 2625rpm . Easy to achieve with the 216.

ps, I have just read you have a 235. My old '56 truck with 235 and 3.9 diff would do an easy 70mph , so your 4.1 diff should still be good for 60mph, assuming the engine has a bit of life left in it

Gents -- please keep in mind we're talking about a 1-ton here. Not the same as talking 1/2-tons (hence the separate forum ), even when swapping bits around -- experience gleaned from 1/2-tons may not apply and could possibly be misleading.

Dave51chev -- I agree, but I wonder if his 15-inch tires are robbing him of any advantage the 4.10 rear gives. Like you say, the online calculator would probably tell us much.

Mike -- Do you still have the original HO72 axle? I hate to be the one to say it, but I wonder if you had left that in place and just switched out the center section, you could have kept your stock wheels and tires and been cruising around with the rest of us 1-ton drivers at 65 MPH not having this conversation ...

And by the way, I've been doing it on bias plys, 3-piece rims and ... gasp .... Huck brakes ... and to quote Morpheus -- "I am still here!"


John

Hi Guys

I got a pair of 31"-32" tall tires coming in the mail hopefully ($212.00 delivered) before the weekend and I also got a pair of modern day (1990's) steel 6 lug 16" wheels ($85.00 picked up)...I am hoping with this set-up I will be able to get to that elusive 55 mph (in a comfortable way)....right now Howard is very very lethargic to say the least...he struggles to get to 53 mph...likes to run more like 40 mph...

I will post on here once I get the new tall skinnies in place and see how it affects the over top end...

I am so thankful I put a disc brake kit on the front end...it does stop great...

Once I get the speed thing then I gotta get the steering modernized too...saginaw front steer...still thinking....hmmmm

MikeC

Stock 16" Chevy truck wheels wont fit the 1985 Chevy K5 Blazer rear end....got the tires mounted too...$35.00 to mount them....ordered a pair of white spoke trailer wheels from wheels express...another $120.00 for another pair of wheels 16"x6" with a large center whole and 6 lugs too....

Not sure what else I can do now....cant wait to see how much the garage will charge me to remount the new tires I just got...

The fun just wont end....

MikeC

Hi Stovebolters....

Just got back from a "speed run" in the Howard Knapp truck...I think my wife said about 50 mph was about it...we were holding our own...put on my directionals on to make a left to make a u-turn and the brandey new disc brakes locked up...so we got up to about 35 mph coming home...smelled like the brandey new brake pads were screaming for mercy...felt like we were trying to push a brick wall I we hobbled home...my wife says it smelled like something was burning...I am leaving it outside just encase something wants to catch fire...don't really wanna lose my garage..

So with 235/85/16's (about 31" tall).....4.10 gears in the rear end and a 4 lane highway...50 mph is about it for Howard Knapp...

scratching my chin right now...

MikeC

Is the engine in good tune? Timing, and valves to start with.
Mine gets up to 55 pretty easy and can cruise there, and it can get to 70 but that's a real push. With an old 228.

Hi Grigg

Everything is as it is supposed to be...timing...valves etc..my motor doesnt even smoke...it even smells like an old truck too..like from back in the day when I was young boy...purrs like a kitten actually....

Thinking about 3.42's in a Chevy Colorado rear end might get me to where I need to be...

MikeC

I think 3.42 will be much too fast for the power you have.

My feeling is the originalish stovebolt 6 might could pull 3.73 gears in a 1 ton but would sacrifice hauling ability. Obviously you could get along better in the flat land than in the mountains. 4.10 seems about right for actually using/working the truck. Mine is quite happy with 4.10 and only occasionally do I wish they were faster gears.

Are you sure you have 4.10 gears and not 4.56 or worse?

Hi Grigg

I took the rear cover off the rear end when I re-did all the brakes on it...It was marked on the gear set 4.10 or 4.11 I am not sure...

I think part of the problem might be...I dont know how this thing is supposed to sound at speed....If I have someone in the cab with me...you cant even talk to them it is so loud...the motor might not be wound out I might not be able to tell it is it ready to blow or not...it might just sound worse than it is...I dont know how a happy 235 is supposed to sound...I use to race one back in 1980-83...it was a straight pipe 250 cu. in. Chevrolet in a 1968 Camaro body....I cant remember how it sounded all wound out...

I am looking for someone in the Albany NY area to come drive it for me....let someone with more experience with these sounds tell me what is going on with it...

MikeC

Good plan.

When I was driving my 235 across the country it ran well and sounded good at about 2,500 RPM all day long, and would tolerate higher but fuel mileage dropped.

I used a TinyTack stuck on the dash, they're simple, cheap, and need no external power to operate.
https://www.tinytach.com/

It might be loud... the door weatherstrip helps some with noise as will a floor mat. One muffler or another can help or hurt in cab noise. I had new exhaust put on in the middle of a big trip and though the old muffler seemed fine, the new one (looked about the same) was much quieter in the cab, a welcome improvement.

Grigg

MikeC, I had 3.42 gears in the rear of my 59 Suburban. (79 K5 Blazer 12-bolt rear). I ran 31/10.50-15 tires on it, I had no problem going down the freeway at whatever speed I wanted (top was over 100). I was running a 350 though, not a 6 banger. Although not a 1 ton, it did weigh close to 5500 pounds. I agree with Grigg though, put a tach on it so you know exactly how fast the engine is spinning.