Send your Gearhead questions to:
- Off-Road Adventures, Gearhead Dept.
- 610 West Walnut Street
- Compton, CA 90220
or email them to:
A Horny Chevy
In an Old Iron article on the Blazer you mentioned that the “Rams Horn” exhaust manifolds were desirable. I just purchased a ’70 3/4 ton 4x4 Chevy that has these manifolds. Do they flow better because of the design? I was going to put in a new GM crate motor with headers. Should I keep the Ram Horns or not.
- Gary
- Houston, Texas
- Via e-mail
The Rams Horn manifolds were better than the majority of the stock manifolds, but a set of headers would be even better. The Ram Horns come into play for rigs where headers cannot be fitted due to space problems, or where no headers are available.
Department of Corrections
We got a heap-o-mail on two Gearhead questions in the Oct ’04 issue, “TTB Tradeout” and “Bowtie Dreamin’.” My chops got busted numerous times over the Bowtie question when I said the last solid axle half-ton Chevy was in ’86. Ok, I know it was ’87. It was just a simple case of brain flatulence, alright! No more death threats! Well, at least we know some of you were paying attention. Good catch, you guys.
As for the TTB Tradeout question, reader Alex made a good case for including some extra information I didn’t think was overly important at the time and didn’t include in my answer; namely whether or not to swap over the track bar with the axle. Alex mentioned that trucks without a track bar may get a front end shake, dramatically called the “Death Shake” by some, if the track bar is not installed. The folks I consulted initially, did not regard it as much of an issue, but in looking further, I think it’s worthy of consideration. The shaking does not come with every Dana 60 swap done without a track bar, but it happens enough, especially in trucks with big tires. It’s probably best that you use the track bar when you do the swap. It’s relatively easy to install, doesn’t impair performance and in many cases the holes are already drilled into the chassis. If you bought a bare axle, the bracket and bar are available separately from Ford or via a wrecking yard. Heavy duty brackets and adjustable bars are available from many lift kit manufacturers if your truck has been lifted.
Vintage Jeep Mods...Or Not
I have a 1947 Willys CJ-2A. Usually that’s all I have to say to make other guys look at me in awe and admiration. Anyway, it’s stock (those other guys seem to have a quiet moment of respect when I say this, too), except for a couple of minor but practical mods, such as a 12-volt conversion, a screw-on filter, and a heater for the aftermarket full cab. It gets cold here in Wyoming! I also have a receiver welded to the front bumper, so I can easily attach my Cummins 9500-pound winch. I can just about go anywhere with it here in the vast, open spaces of southwestern Wyoming. Are there any mods you’d recommend?
- Karl Jackman
- Lyman, Wyoming
A Cummins winch, huh? That’s a new one for me. Anyway, Karl, you have a classic rig that is steadily appreciating in value. If you keep it stock, or at least make only minor bolt-on changes (saving the original parts), it’s more valuable. Also, if it’s doing what you want it to do, why mess with success? Still, here are a few ideas. First, install a Pertronix (www.pertronix.com) electronic-ignition conversion. It’ll help make that old flathead fire up on the coldest of days and run like it hasn’t for years. I’d suggest a locker or a limited-slip for the rear, but the applications for your Dana 41 are limited to one: the PowerTrax Lock Right. It works well if raw traction is needed, but it can be noisy and a bit spooky on ice. A wide selection of limited-slips and lockers are available for the front Dana 25 if you want to go that way. About the biggest tires your axles will take are 31 inches tall. In the old days, people used to install 7.00-16s (roughly equivalent to a modern 225/75R-16, about 30 inches tall), and if the springs haven’t sagged too much, they might be a no-lift answer. Rancho still offers flatfender kits with one- or 2.5-inch lifts. A 2.5-inch lift would be enough for 32-inch tires (a 235/85R-16 or 7.50-16), but I think that might be too much tire. Overall, get a tire with a fairly aggressive tread, but shy away from really wide tires because your axles are old and weak. Also stick with tires no higher than load-range C. The load-range D and E truck tires are too stiff for a lightweight Jeep like yours.
All Six Inches
Not long ago, I had a six-inch suspension lift installed on my truck. After a few months, I’ve realized that, after parking the truck side by side next to another truck with the same lift, my truck sits lower. How can I check to see if I really did get a six-inch lift?
- Big Joe
- Via e-mail
Good question, Joe, though you didn’t give me much info to work with. There are a number of variables that affect how much lift you actually end up with. The first is vehicle weight. If your rig is heavier than your buddy’s, either by having a bigger engine (V-6 versus V-8, big-block versus small-block, etc.) or is carrying more gear, it will compress the springs more and sit lower. Many manufacturers will offer standard or heavy-duty spring rates. If your rig is on the heavy side, go for the higher spring rate. Remember also that tire size will affect perceived vehicle height and that one manufacturer’s mounted size may be larger or smaller than another’s, even if both sets of tires are listed as 33s, 35s, or whatever. As to how you can check, do so by measuring before and after. If your kit is already installed, it’s too late unless you can find a stock rig exactly like yours was (tires and everything) to take measurements from. Most people measure from a section of the frame rail to the ground, front and rear, both sides. You didn’t mention a brand name for your kit, but I can’t think of a lift-kit manufacturer that wouldn’t be happy to help you work this out, so give their tech line a call if my advice doesn’t carry you to a good solution.