Question: I have been reading and subscribing to your magazine on and off since I was 10 and when you're that little, you're always running to the mailbox hoping the next issue was waiting.
Now 26, I have acquired my dream rig. It's a '67 F-250HD Hi-Boy. It has a swapped-in 390 that I put chrome fenderwell headers on, factory 4.55:1 and 4.56:1 gears in the HD Dana 44 front and Dana 60 rear. It has the NP435 trans, which I was very happy to read is a good unit with a killer crawl ratio, and finally the Dana 24 transfer case. In stock suspension form with no lift it clears 35s with no problem.
My question is this: for purposes of a functional 4x4 that I can really enjoy while retaining the restoration look, which driveline component is my weak link? It has enormous knuckles and locking hub units. I do want to lift it for 40s since 38s just don't look big on these trucks. This probably isn't smart with a Dana 44, but would 38s work? Can I twin-stick the Dana 24 case? I'd love to build it as a nostalgic-bodied functional 4x4 prerunner, but for now I'll shoot for hearty trail rig with the bead-locked, rock-slider look.
Yucca Valley, CA
Answer: It sounds like you have built yourself up a pretty nice classic Ford truck. Not knowing just how hard you romp on this truck, and to be on the safe side, I am going to say that in all honesty that I think you should stick to your present 35-inch tires. OK, they may look small to you, and the 38s or 40s would make this truck look even cooler. While you have the big knuckles and hubs on the 44 and a full-floating rearend, you still have 1 5/16-inch, 30-spline axleshafts in the 44 and 1 5/16-inch, 16-spline axleshafts in the rear. If you were using these components in a lightweight rig, then I would say go for it, but in your fullsize truck, I think that you would be asking for, well, broken axles. I know, I know, you see in the pages of this magazine (and other truck mags) people running 38s on even smaller axles. That doesn't mean that they really use these vehicles hard or that they don't break axles all the time. I guess it comes down to how hard you want to use your truck and how often you want to replace axles-that is, if you can even find stock axles.
Now this brings up another point. You could always contact one of the custom axle makers and have a set made out of quality material. While you're at it, you could change out the spider gears in the rear for a set with 30-splines to upgrade the axleshafts.
If you don't plan on really serious trails where you're going to be really working those axles hard, then go for the 38s and keep your fingers crossed.
Question: I have a '90 YJ that I'm dropping an AMC 304 in. I've already found my motor mounts. Could you please give me a list of other components that are required, and where to find them? Also I'm trying to find a set of headers for the 304 that will fit with my auto tranny.
Answer: I've never heard of anyone putting a 304 AMC motor in a YJ, but I don't see any reason why it can't be done. Wow, a list of everything that you will need and where to find them? That's tough. Well, Novak Conversions (877/602-1500, www.novak-adapt.com) has an aluminum radiator (PN CR1166-2) that will bolt in. It's designed for Ford conversions, but the AMC motors have the hose fitting in the same location.
I would think that for throttle linkage, you could use the parts from a CJ V-8 Jeep. This should still be available from a Jeep dealer or most off-road shops. Crown Lokar (877/469-7440, www.lokar.com) has some really nice custom throttle linkages.
Now as to headers, I have no idea. Hedman (562/921-0404, www.hedmanheaders.com) offers at least four different configurations of headers for the AMC engine, so you might give them a call and see if you can get some measurements.
One thing that you really need to keep in mind before doing this swap: Will it pass an emissions test in your area?