Posted by Vaughn [162.158.186.163] on Thursday, March 16, 2023 at 06:42:49 :
In Reply to: Axel width GM corporate 14 bolt posted by Mike M [172.71.254.198] on Wednesday, March 15, 2023 at 23:40:47 :
The FFPW track width is 64-3/4 center to center of tire, you pretty much want to stay close to that, if possible, and adjust for wider rims/tires.
You'll need to do a few measurements depending on if you plan to stay with stock rims or go with aftermarket. If you stay with stock rims, center-to-center of tire will work for track width and you'll need to consider the following measurements as well, especially for wider tires and for a front differential.
If you go with aftermarket rims, you'll want to measure the differential wheel mounting surface-to-surface (WMS), where rim bolts to hub fir differential width, and measure the positive or negative offset of a rim, and distance from the side of a max turned FFPW tire to springs for the front and side of a rear tire to closets bed part so you can ensure you have enough clearance, to make the best differential, rim/tire choice.
The Single Rear Wheel (SRW) is probably what you want to look at unless you want to go DRW and there are several widths to choose from to get you close to where you need to be to avoid tires rubbing or being too far out of the fender well, see link.
The article at this link will help explain rim offsets.
https://www.jegs.com/tech-articles/everything-you-need-to-know-about-how-to-measure-a-wheel-size-offset-backspacing-more/
As far as the tire size and axle ratio, no lower than 4.88 for 38", 5.83 for 40" if you're using a 230 engine. The bigger tires are heavier and will take more power. I have the 230, 4.89, 38" 1100-16, and it takes a good amount of throttle to work the engine at 55/60mph at 60 pounds of air pressure. Hauling a load or going up grades under powers the 230, so I'm transitioning to a Chevy 327 with an SM420 trans, the truck just needs a little more power for the change in ratio and tire size, and you may find the same after doing some changes.
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