'75 Duster steering issue
72blunblu, I was going by suggested alignment settings for typical performance street. Maybe this is for manual steering boxes?
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The SKOSH chart you posted is a good start, but you have to keep in mind how old it is at this point and where it came from. It was originally published in 2005, by Rich Ehrenberg. You can see a copy of that article here
Turn of the screw: front end alignment for performance...
So, you have to keep in mind that was before the entire "pro-touring" movement and really upgrading these cars to handle well. Yeah, Rich was putting the "Green Brick" together at the time and you could get tubular UCA's from Firm Feel that had more caster built in, but they had pretty much the only game in town. The +4° of caster listed in the chart was pretty much the most you could count on getting at the time unless you made your own parts. The offset UCA bushings with factory UCA's were what most people were using, and with those +3.5° is about the most you can reliably get on most cars. And very few people were building their Mopars for handling then. I bought my Challenger in 2008 and can tell you that Firm Feel was pretty much the
only source for handling parts, and the were only a handful of people on these forums that were concerned with handling.
I'll get to the point. The numbers in the skosh chart for caster are pretty conservative and a bit outdated. Even just a few years later (2011) I was running my Challenger with +5° of caster, using tubular upper and lower control arms and adjustable strut rods. And the tubular LCA's and adjustable heim jointed strut rods were a very recent addition to the market at the time.
Ultimately, it depends on what you're comparing it to. Unless there's something wrong with the steering box itself, or your steering linkage is adding too much resistance, the return to center action you'll get from +2° of caster is pretty weak. With power steering I wouldn't hesitate to dial that up to +5° even on just a street cruiser. The settings I run are more than most run on the street, but I've run everything from +3° caster all the way up to +8°, and my personal preference is around +6°. That's with a fast ratio manual steering box and 275/35/18's up front.
I don't know how much you've driven one of these cars, or how much you've driven one recently, but if you're comparing the return to center feeling of something built in this century to what you have with your '75 you'll likely need to add a significant amount of caster to put them in the same ballpark.
