A In my view the TBI 350 is one of the most dirt-simple fuel-injection systems out there, and swapping one into an earlier Chevy is pretty easy. You can get a great wiring harness from Painless Performance (817.244.6212, www.painlessperformance.com) with all the connections labeled and the engine should bolt in where your '76 350 is currently. You'll need to add an electric fuel pump or look into one of the mechanical Race Pumps (336.476.9720, www.racepumps.com) for fuel injection. The ECU from the '88 will be needed as well. And though the TBI power isn't the top of the line compared to some crate engines, it's still reliable and strong enough for most trail wheeling.
Q I decided to put a fuel cell in my truck, but heard I should ground the fuel cell. How would I go about doing that? Where do I attach a cable? Or do I even use a cable?
A Yes, I spoke to the crew at JAZ Products (800.525.8133, www.jazproducts.com) and they recommended attaching a grounding wire to the steel fuel filler neck of the fuel cell and running it to the chassis. If you have a steel or aluminum tank, you can run a grounding strap from anywhere on the tank to the chassis if it is not mounted to the chassis already, but definitely run the grounding strap on plastic fuel cells.
Q I have an H3 with a leveling kit. I like the gas mileage I get with the 33-inch tires; however, I like the look of larger 35s. Would it be smarter to purchase 35-inch tires and mount them on the factory rims with new gears, or put them on new rims that I would then swap on when I hit the trail? If I get the gears, would my gas mileage stay the same?
A Even if you match the ring-and-pinion gearing to the new tire size it's doubtful you will keep your current fuel mileage. The added weight of the bigger tires, the larger rolling resistance, and the decreased aerodynamics of the larger vehicle are not going to help, so I'd definitely recommend a second set of tires for your Hummer for off-roading. Unfortunately, the lower gearing would help you when off-road by maintaining a factory-spec powerband with the taller tires, but luckily the H3 comes with either 4.10:1 axle ratios stock and many are equipped with a 4:1 low range in the transfer case so hopefully you have the lower gears in yours and I believe you will be fine with the slightly larger 35s off-road.
In this time of astronomical fuel prices it makes sense to watch everything that can help squeeze extra miles from every gallon. Unfortunately most off-road upgrades do not aid mileage. That being said, I like your plan of simple bolt-on additions that can transform your truck before an off-road trip and then be changed back before your next drive to work. Though it may be a little extra work, it is a good way to have your cake and eat it too.
In fact, there are many tricks to upgrading your 4x4 for off-road use that can then be removed after the weekend. For example, a receiver-mounted winch, off-road lights with quick-disconnect wires, and even leaving your heavy tool and recovery bags at home during your daily commute can reduce weight and save fuel. In the perfect arrangement you'd have a set of 35-inch aggressive mud-type tires for your off roading and then some narrow 33s of a milder street tread that you run at higher pressures during the weekly commute. Things like exhausts and intakes can have mixed results depending on the manufacturer, but the theory of a better breathing engine should produce mileage gains. I haven't tested enough of these to tell you which make is proven.
Since saving fuel is an important step every off-roader should consider, I'd like to award you this month's Nuts, I'm Confused letter. To help you get started saving fuel and continue wheeling wild trails, I'd like to award you a new set of Classic style wheels from Mickey Thompson. These highly polished wheels will look great either as your street or trail rims and will get you started on a backup set of wheels and tires for your dual-personality Hummer. The wheels are available in 15x8, 15x10, 16x8, 16x10, 16x12, 16.5x9.75, 16.5x12, 17x9, 18x9, and 20x9 sizes to fit most popular truck and off-road applications.