6.0 ls swapped 95c1500

[nhyrum]

It's the lower profile that has stiffer side wall. Think of it as a line drawn in arc. Quarter circle. That's the movement in a 60 series tire. Take away a third of that arc line now you have less available movement 50 series. Therefore same plies but less movement equals stiffer sidewall, less roll, more contact footprint.
Higher pressure for racing short time is done regularly. But everyday causes wear issues.

Right. It's hard to find a low profile tire in a 15 inch wheel that is tall enough, and I don't know how big a rim i need to get a low profile street tire, hoping to stay around 28 inches tall. I don't think I'm going to stay with a 15, just don't know what size. I don't think I want anything bigger than 18

 

[nhyrum]

There's lots of good tools on this page, both the comparison calculator on the left and the comparison charts further down the page, that might help you find something. I've got some 275/55R17 Toyo's that handle a lot better than the 275/60R15 Radial T/A's I had previously. I found the T/A's would roll the sidewall pretty easily when turning so I ended up running a significantly higher pressure in them.

I've used that tool to get a good dimension.

I think a 275/55r17 might be my size.

Any idea on what would be a good backspacing for a standard gmt400 if I got a 8.5"wide wheel

 

[Drunkcanuk]

I wanted to stay with 15's on my truck, to keep it "period correct". Was researching tires for them and basically the companies have "moved on" from them, new technology and such.

Then I came to the conclusion that it didn't take long for the "big 17's" to takeover the scene and the trucks I fell in love with in the magazines. I ended up going with 17" wheels, 235/65/17 Toyo Proxi II for rubber. Didn't want anything bigger. They are the same diameter as stock.

For me they look "right", not too big, but bigger than stock, the tires are "lo pro" compared to the
235/75/15's but have enough sidewall to soak up bumps. That's my theory anyway, haven't driven it yet!!! Lol

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[GoToGuy]

So if you look at the tire charts that he posted you can swap the numbers around to get what you desire. If want you a specific diameter you trade around rim size and profile.
In case you didn't know the profile is approximately the percentage of tire width. ( 55 is about half tire width)
So I went with 265/ 70/ 16 about 7/16 taller than originally so my speedo is 3 mph under actual ground speed.
My tires are 31.5 " tall and have 3.73 rear. 2100 rpm 65 mph. Have checked your RPO codes for what axle and ratio is installed? And what was your oe tire size? The smaller ( in diameter ) you install than OE the higher your effective axle ratio, 3.55 could turn into 3.65 and so on. Hope this helps, good luck!

 

[Shwa Kid]

I think a 275/55r17 might be my size.
Any idea on what would be a good backspacing for a standard gmt400 if I got a 8.5"wide wheel

I'm guessing there's a wheel thread in here somewhere with tons of photos, but here's my truck with 275/55R17's on 17"x9" Cragar Soft 8's with 5" backspacing I'm almost positive they were p/n 3978950.
This was lowered 2/4 with coils in the front, shackles and hangers in the rear. Fitment was pretty much perfect once I rolled the front fenders.

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[nhyrum]

So if you look at the tire charts that he posted you can swap the numbers around to get what you desire. If want you a specific diameter you trade around rim size and profile.
In case you didn't know the profile is approximately the percentage of tire width. ( 55 is about half tire width)
So I went with 265/ 70/ 16 about 7/16 taller than originally so my speedo is 3 mph under actual ground speed.
My tires are 31.5 " tall and have 3.73 rear. 2100 rpm 65 mph. Have checked your RPO codes for what axle and ratio is installed? And what was your oe tire size? The smaller ( in diameter ) you install than OE the higher your effective axle ratio, 3.55 could turn into 3.65 and so on. Hope this helps, good luck!

Right, what I was really looking for in tires was something that was the height I wanted, but also a tire size that is popular. All the sizes that I liked the dimensions of only had like two tires available.

I've got a picture of the stamping on the ring gear. I changed the diff oil a while ago and knew I'd need to know what was in there. It's stamped "1 12 41 10 94"
After some lookup, is got 3.42 gears. With the current tires it has, that are 29 inches tall, the Speedo reads about 5 mph fast at 30, meaning you're actually going 25. I tried messing with the drac/vssb thing behind the glove box(truck is a 95) by soldering in jumpers in different places, but that didn't do anything. Anyway, with the swap, I'll be getting rid of all that so it should be as easy as having the ECU programmed right.

I think I may go to a set of 17 inch wheels. My current 15's are too narrow to run something 10.5 anyway. Not to mention it's hard to hide something like a Mickey Thompson 28x10.50. with a 17 I can get sporty tires, but if I wanted a set of slicks, I can find a 28x10.50 in a 17.

My next task is just to make a 28x10.50 fit and figure out the backspacing/offset I need, and if I want to have the front be the same width as the rear. I've got no need, other than not really wanting to have two separate tire sizes. I don't have direct access to the truck, but I've got plenty left to do on the swap before I get to rubber.

 

[L31MaxExpress]

I apologize in advance, I can sometimes tend to over think and over complicate things, so if any of what I say is way out of left field, let me know.

I'm working on putting in an 04 lq4 into my 1995 c1500. And I've got a few questions while I work on things, like finishing the engine rebuild, and getting a good trans, and other parts and pieces I know I'll need

My end goal is a build that I don't cut any corners, and I want things to last. I am shooting for something around 600 whp, that will get driven "regularly" but not completely a daily driver.

I've got the engine, minus accessories, and, I believe, both a DBW and DBC throttle body for it. No wiring harness or ECU. I'll be getting an 0411 ECU. engine spun the#1 main, so I had the block machined, new rings and bearings, rings gapped so I can add boost later. Btr truck norris cam and brt springs.

Fuel pump is a walbro 450, -8 an supply, -6 return, Holley 76lb injectors

A few questions I have now are

1) the truck didn't come with factory cruise control. How hard would it be to add? Will I have to be DBW for it?

2) can I have some sort of traction control? Does the 0411 PCM have some kind of capacity like that? Would it have to be DBW? No big deal if it's not able to.

3) ps pump and lines. I need a ps pump, and I'd like to go hydroboost breaks, which I believe run off the ps pump? I believe there was a pump that worked better for hydroboost? What pump should I get? I'll also need new hoses, as the old ones were cut.

4)"economy cruise" tune? I'd like to have two tunes for it, ideally. If it even makes sense. Something that's kind of like a highway cruising economy tune, and a "daily driver, but still knocks tires off" but not quite "street strip" I don't really plan on messing with tuning much, I won't be changing anything in the tunes, that I'll have professionally done. Is it easy to go in and swap tunes with hp tuners? Does it even make sense to have two?

5) flexible brake lines. I'd like to replace the aged rubber brake lines, are braided stainless lines the best? I've heard problems with grime and grit getting under the braiding and causing issues. I know they'll still have some expansion, but better than rubber. Is there something that's still flexible enough for the suspension travel(at least up front) but rigid enough to not swell under pressure?

part of me wants to take advantage of all the features of a computerized system (traction control, lean cruise, shutting off fuel for coasting, etc), but at the same time I want to be directly connected to the engine, and don't want any delay.



I'm sure as I get further along I'll have more questions.

The correct tuning makes both the best fuel mileage and the most power. No need for two tunes.

You can easily add cruise with both DBC and DBW. DBW is easier because it only takes a stock cruise switch and a few wires to the TAC module.

Traction control is part of the tuning and tied into the ABS module. DBC stuff with traction control used a module that backed off the throttle.

 

[Erik the Awful]

The correct tuning makes both the best fuel mileage and the most power. No need for two tunes.

A tune that makes the best power doesn't necessarily make the best fuel economy. A tune that makes the best fuel economy doesn't necessarily make the best power. I believe @L31MaxExpress is saying that there is a nice middle ground that you need to target. I need to get my Mustang's speedometer corrected and for a few hundred more I can get a tune. A coworker who's been to the local "famous" tuner told me to make sure he knows that it's a daily driver, or he'll sacrifice fuel economy to maximize that last few horsepower.

 

[L31MaxExpress]

A tune that makes the best power doesn't necessarily make the best fuel economy. A tune that makes the best fuel economy doesn't necessarily make the best power. I believe @L31MaxExpress is saying that there is a nice middle ground that you need to target. I need to get my Mustang's speedometer corrected and for a few hundred more I can get a tune. A coworker who's been to the local "famous" tuner told me to make sure he knows that it's a daily driver, or he'll sacrifice fuel economy to maximize that last few horsepower.

No I am saying I can tune both tunes into the same tune without sacrificing mileage or power. No need for two seperate tunes. Want mileage be easy on the go pedal. Want power, put the pedal down. Want to alter the transmission shifting, use the Tow/Haul pattern for Performance or Towing and Cruise control shift pattern for highway economy. It can be optimized for both fuel mileage and power in the same tune. The position of the throttle switches the tune from economy to performance back to economy instantly. My 383 goes from Dr Jekyll to Mr Hyde merely pushing on the go pedal, then when I back off the pedal it is right back to Dr Jekyll.

 

[nhyrum]

No I am saying I can tune both tunes into the same tune without sacrificing mileage or power. No need for two seperate tunes. Want mileage be easy on the go pedal. Want power, put the pedal down. Want to alter the transmission shifting, use the Tow/Haul pattern for Performance or Towing and Cruise control shift pattern for highway economy. It can be optimized for both fuel mileage and power in the same tune. The position of the throttle switches the tune from economy to performance back to economy instantly. My 383 goes from Dr Jekyll to Mr Hyde merely pushing on the go pedal, then when I back off the pedal it is right back to Dr Jekyll.

A Jekyll/Hyde tune is perfect. I would like to have something where the truck is still well managed, still able to be opened up and make use of the tires I get.

I need to figure out my fuel system, but regardless I don't think I'll be using a Corvette filter/regulator. I don't have easy access to the engine and I can't remember what take I have, but it's an lq4 from an 03 or 04 Yukon Denali that was DBW. Ithink my primary obstacle is going to be myself. I'm trying to "future proof" the truck as much as possible. NA I'm thinking I should be around 550-600, and when I've been doing turbo research, I'll be at the limit of my pump and injectors at about 8 lbs boost, or 800 hp on E0 pump gas. Another walbro 450 and bigger injectors is all I really want to do if I reach that limit, so I want a fuel system that can handle about 1000 on e85 or pure ethanol. I've got 20 feet of-8 PTFE for fuel. Aeromotive and Holley both make EFI filter/regulator combos, or should I get a separate filter and regulator? I'll be wiring for both pumps and leaving the second pig tail tied up and probably capped, and leaving room to plumb, and maybe even make, the y for the second pump outlet(changing to a 2 in one out filter maybe?)

If I have the return system, is the pressure related at the rail with the truck intake, or would I need a pressure regulator?