I read the story "Axle Axtravaganza" in the May '07 issue, and there was a lot of good information. However, I was disappointed there wasn't a photo for each axle listed to help identify them in the junkyard-or at least to satisfy my curiosity. My local chop yard has an old Jeep chassis rotting away, and I wanted to know if the rear axle is a Dana 44 or Dana 41. How do I tell them apart?Stan FullerMadison, Wisconsin
While we'd like to have been able to run a photo of each axle for that story, it would've turned a four-page story into a 10-page story. Sometimes we just don't have the room for all the stuff we want to do in these pages.
The Dana 41 was found under '46-'49 CJ-2A and midyear '49 CJ-3A universal Jeeps as well as some '47-'50 four-cylinder Willys wagons and pickups. Both versions will have the differential offset to the passenger side for use with the Spicer 18 T-case, but the CJ rear axles will measure 50.5 inches WMS-WMS, while the truck and wagon versions are wider at 59.5 inches WMS-WMS.
Compared with the Dana 44, the Dana 41 has a much more oval-shaped 10-bolt cover. With the cover removed, there's a distinctive resemblance to a lemon when stood on its end. Also, the ring gear is very thin compared with the Dana 44's and extends beyond the diameter of the carrier. Finally, there should be a clear "41" cast on the lower passenger side of the pumpkin (arrow).
I also purchased the 290hp Chevy 350 long-block from GM to replace the 350 in my '72 K20. I went with a GM HEI distributor, an Edelbrock Performer manifold, and a rebuilt Q-jet versus the Edelbrock carb due to linkage problems. I have the manual transmission and 4:10 gears. I question whether this engine is the right choice for trucks or Jeeps.
The engine lacks the low-end performance I need to haul my camper. If you look at the power and torque curves, you need to be near 3,000 rpm to start seeing any response. Maybe I have it set up wrong, but I believe the cam is not the right choice for the applications we're talking about. My engine only pulls about 2 Hg vacuum at idle.
You're right about the long-block price (great value), but it will nickel and dime you to death to complete the build. The biggest pain has been getting pulley and belt alignment right. I was ready to pour gasoline on it and burn the truck to the ground at one point!AnonymousVia e-mail
You've got to remember-and I said it in the story-my truck has 5.89 gears and only 38-inch tires, so I'm in the 3,000-rpm range virtually all the time. I also had a running (more or less) 350 to start with, so it only took me a weekend to do the engine swap and put all the components from my crap engine to the new one; I really had no issues. Sorry you had a different experience.
The cam is actually a good match for those cylinder heads. They breathe so poorly compared with modern heads that you've got to hang the valves open a while longer to get any air/fuel mixture into them. Hell, it's making 250 lb-ft of torque right off idle. That's not bad.
If you're looking for low-end grunt without giving up top end, you can always swap to a Comp Cams Xtreme 4x4 cam (PN 12-409-8). It's got an advertised 258/262 duration and 0.458 lift, but with only 206/210 duration at 0.050, it'll build more cylinder pressure. Or if you're just into low-end torque, put in a 252H cam (PN 12-205-2). That'll bump the torque up into the 360-lb-ft range, but your top end will suffer slightly. Or if you don't want to swap cams (it's such a pain in the ass getting the timing chain cover to seal on a small-block Chevy) and really plan on keeping that truck and engine for a while, you can bolt on a pair of GM Performance Parts fast-burn heads (PN 12464298) with 1.6 roller rockers (PN 12367346) and get an extra 70 hp and 45 lb-ft of torque. It's an expensive upgrade, but still cheaper than an HT383 engine.