'CC Quickies
Thrash
We came upon this scene right after some NMCA guys pulled, rebuilt, and replaced their broken transmission between rounds. There is a valvebody and some dead clutches in the cardboard box.
Shocks are also an important addition to this setup. Just about every shock company you can think of probably has a damper for your truck. If you are really serious about improving handling and willing to do some testing, then an adjustable shock absorber is a serious consideration. Of course, adjustable shocks are expensive, with the double-adjustables the most costly. A single-adjustable shock allows you to tune one-half of a shock operation, usually the compression side. A double-adjustable shock will allow separate tuning of compression and extension. We've had very good experience with QA-1 shocks. The single-adjustable PN for the front is TC1914P; the rear is TC1539P. Both are priced at $139.95 each from summitracing.com. For double-adjustables, just add a D to the front of the part number. The double-adjustables go for $299.39 each, so you better be serious about being competitive.
It would also be a good idea to upgrade your front sway bar. The stock front bar is a 1-inch diameter bar and could be easily upgraded in several ways. Addco sells a 111/48-inch front sway bar (PN 739, $149.88), or we've heard that the ZQ8 late-model front suspension upgrade used on the later-generation ('94 and newer) S-10 Xtreme is 33 mm (1.30 inches in diameter) and might work well. The key is to determine which bar will work best for your vehicle. You might be able to get by with the stock-diameter bar with the new springs. If not, the Addco would be an improvement. The ZQ8 bar may be too large since it is designed to be used with softer production-rate springs. I think you'll find that you will not need a rear sway bar (as used on the later-model Blazers) because this will create a too-stiff situation that will hurt handling, making the truck tend to oversteer on corner entry and exit.
'CC Quickies
Random Pit Dog
A good limited slip is an absolute necessity for what you will be doing. This is especially critical for an autocross application where applying power (with very little weight in the rear) in a low-speed corner will want to spin the unloaded inside tire. A typical clutch-type limited slip like an Eaton (PN 19557-010 for 28-spline axles, $479.95 at summitracing.com) is a good choice, but we really like the Eaton Detroit Truetrac differential that uses gears as opposed to clutches to create a stronger torque bias between the two rear tires. What's even better, this unit for the S-10 8.5-inch rear axle (PN 912A557) is only $409.95 from summitracing.com and does not require a special limited-slip gear lube additive.
Of course all this suspension tuning is really not going to really pay off until you step up to a big set of sticky tires. We're not conversant on what size fits these trucks once they've been lowered, but we know that a 16x8-inch wheel with 245/50R16 tires fits on all four corners. We'd shoot for a 17-inch version of that with perhaps a 255/45R17 on the rear for more grip coming off the corners. As for your question on making the rollbar fit through the rear window, we'd suggest removing the rear glass and using a sheet of scratch-proof polycarbonate. Cut it out to clear the rollbar tubes, seal them up, and you're ready to run. Percy's sells a product called Speedglass. You can buy this material in sheets that can be easily trimmed to fit.
More Info
Addco; Lake Park, FL; 800/338-7015; addco.net
Eaton Automotive Group; Southfield, MI; 800/386-1911; eaton.com
Eibach Springs; Irvine, CA; 949/752-6700; eibach.com
Global West Suspension; San Bernardino, CA; 909/890-0759; globalwest.net
Percy's High Performance; Linn Creek, MO; 888/737-2970; percyshp.com
Rock Auto; Madison, WI; 866/762-5288; rockauto.com
Summit Racing; Akron, OH; 800/ 230-3030; summitracing.com