Retrofitting Chevy EFI To Carb
Question: I have an '89 Chevy 1-ton 4x4, and I want to get rid of the TBI and go with a carb and intake. Is this possible? It has the OBD-1 computer and a Turbo 400. I have just rebuilt the engine, bored 0.030 over, and with the biggest cam that can go with the computer, and it runs OK but I feel there is more in there. We ran the track at 13.90 in the quarter-mile, but I feel that the TBI and the computer are holding it back.
Brent Broersma
Camas, WA
Answer: Yes, the low airflow of the throttle body is holding your performance back. You might consider swapping one from a "big-block" motor, as they are a bit larger and do flow more air. (Whoops-my guess is that your 1-ton is already equipped with a 454, as I believe that was the standard motor for them at that time.) Now, if you go to a carburetor, I am sure you will see a performance increase, but you also will be in violation of state and federal laws as far as emissions requirements.
Aside from that, let's assume you only use your truck on private land. You need to carefully pick the proper manifold and carburetor for your application. Trying to recommend something is pretty difficult considering that I don't know your present cam specifications and rpm range of operation. My choice would be something a bit on the conservative side, so pick up a Summit Racing catalog or take a look at www.summitracing.com, as there are a lot of manifolds available.
As far as a choice of carburetors, I think that I would go with a Holley Truck Avenger in either the 670-cfm or perhaps the 770-cfm version as I have had some pretty good luck with them in off-road situations, and they are quite easy to tune.
Keep in mind when picking both the intake and the carb, that you want to retain that low-end torque that the 454s are famous for, as you're moving a pretty darn heavy truck.
Oh, and you're also going to need a new distributor; the computer-controlled unit will not work properly. You can either use an early-model factory HEI unit or one of the aftermarket brands such as an MSD.
Lift Tips For 3/4-Ton Ram
Question: I have an '02 Dodge Ram 2500 4x4 with the Cummins diesel, and I was happy to see it on your "Best Buys in Used 4x4s" list roughly a year ago. I have no complaints, as the truck has been very good to me. I use it for work and load it up pretty good sometimes.
If I bought a 6-inch suspension lift, would the new springs be able to handle a heavy load like the stockers? Which is better-a body lift or a suspension lift? I thought a body lift would keep the center of gravity lower. It already has stock 5-inch lift blocks on the rear springs and 2-inch coil spacers on the front. I bought a 3-inch body lift kit for it, but haven't installed it yet. I'd have to disconnect practically everything under the hood for brackets. It seems like a lot more work than putting in a spring lift. I want to put on some 35- or 37-inch tires. What do you recommend?
Jonny Brown
Shrewsbury, MA
Answer: Body lift kits are an inexpensive way to get additional clearance for larger tires, but you do pay the price in the fact that there is one heck of an amount of hard labor involved, and lots of bracketry that has to be moved and extended to make it all work right. Your statement "that you load it up pretty heavy some times" makes me wonder if the body lift is not something that you want to be using, especially one that moves the body away from the frame 3 inches. This puts a lot of leverage on the body mounts, spacers, and bolts, and could result in the body moving around a bit when you don't want it to.
As to whether the 6-inch suspension lift would be able to handle the extra weight when the truck is fully loaded, most companies take this into account, but I would suggest that you check with the company that you consider getting the kit from. First off, you really do want new rear springs and not just another spacer block, especially one that will add another 6 inches to the present one. You want to make sure the springs are capable of handling the same amount of load that the factory stock ones are. Keep in mind that a 6-inch suspension lift will also, generally speaking, make the truck ride quite stiff when unloaded and probably won't really add all that much to its articulation ability.