Re: [Amc-list] Rebel Station Wagon upgrades- Brakes, 4.0, Auto O/D

[Frank Swygert <farna@xxxxxxx>]

The 87-90 4.0L was rated at 177 hp (Renix injection system), the 91+ 190 hp. I think the real power rating for the earlier one is closer to 190, I never noticed any difference when driving the two. I think Chrysler just rated the engine less conservatively than AMC always did. A 1972 304 (first year of net power rating) put out 150 hp, so the 4.0L beats it by 40 hp. The 4.0 rates 225 ft/lbs of torque, the 304 245, but the 304 comes in at 2500 rpm, the 4.0L at 4750. A 72 360 2V rates 175 hp/285 ft/lb; 4V 195 hp/295 ft/lb. I'd place the 4.0L squarely between the 304 and 360 -- sort of like a hopped up 304. The 304 produces a bit more torque, but the 4.0L torque curve is flat and it produces a lot of torque at low rpm. The rating is where it peaks; most driving is under 2500 rpm though. The 304 peaks in torque rather early -- I was surprised by that! The 258 peaks out between 1600 and 1800 rpm. 

The 4.0L is clearly a better choice than a 304 for a driver. That wagon probably weighs about the same as a Cherokee, and I'd expect performance to be about the same. The only advantage of a 360 is that there's a lot more potential if you decide you need more power. There's not a lot you can do to the 4.0L to get much more power without a lot of $$$. It's closer to it's peak potential output. You can get maybe 20-30 hp with easy, relatively inexpensive bolt-ons, but that's about it. 

Stroking the 4.0L with the 258 crank and rods is the best option for more power if the 4.0L needs rebuilding anyway. It's not quite that simple -- you either have to dish the pistons or get a cam that will bleed off some cylinder pressure. Either way works about the same, though some think the cam solution a "band-aid" fix (I don't -- just another way to skin a cat, and it's cheap and easy if replacing the cam anyway). You need bigger injectors also, but that's about it. Power with the bleed-off cam still comes up to around 260-265, and you will lose about 2-3 mpg on the highway, 3-4 in town. That's what I lost when I went from a stock 4.0L to a 4.6L stroker -- same driving style for both. I don't exactly baby my cars, but I'm not hard on them either. 

You have an AMC 20. All the big cars got the 20 even with a six (except for a few fleet 67s that also got 199s). The AW4 auto O/D will need a lot more gear than the wagon has now. The old torque converters multiply torque by 2.5-3.0:1. The AW4 high efficiency torque converter only multiplies 1.4:1. The big torque multiplication factor is why the old cars could use a high gear with an auto trans. The AW4 will need a 3.54 or 3.55 gear. You can modify the Comanche axle to fit the Rebel, at least I think the width is about the same (the Comanche wheels are deep inset). Would take some fabricating to get the top arms to work right, but might be easier/cheaper than replacing the gears in the AMC 20. That will run around $300 if you take the axle out and drop it off to a shop. Gears are around $150, about the same for labor to set them up right. 

All the brakes interchange about the same, as Mark mentioned. You can use later Concord discs on the big cars, they work just fine. They will heat up more than the thicker big car brakes, but unless you plan on using this thing to tow with a lot it's nothing to worry about. If you plan on towing a car trailer get a trailer with brakes and you still don't have to worry about overheating the later brakes.  I wouldn't tow a car trailer much without brakes, don't even like doing it with my bro's F-250 diesel dually. Don't care if it has big brakes, the more tire patch braking the better! 

I'd say that the WSC rear disc kit is the best, but there are others. I wouldn't worry about rear discs either. The big drums should be fine, and a trailer should have brakes too. Wagons got bigger drums on the back due to expected larger loads.  

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Date: Wed, 10 Dec 2008 18:28:49 -0800 (PST)
From: Jesse <j2sax@xxxxxxxxx>

OK, so it looks like my search for 71-73 Matador Wagon may end with a 67 Rebel Station Wagon.  It has a 258/auto but the front floorboards are shot due to sitting and water leaking through the vent system.  Some questions concerning upgrades.  

1.  I have a 4.0 with O/D auto from a Comanche.  Rather than modifying a 258, I think this would be a simpler effort to having EFI and an O/D trans.  So, how would a 4.0 do as far as output goes?  I have an 88 with a 99 intake and header.  

Of course, I could do the stroker thing and have plenty of power, at the expense of some mileage I expect.  

I also have a V8 crossmember... could do a 304 or 360.  I have never had a full size with 6 cyl, so you're experienced opinion is appreciated. 

2.  Since this has front discs, is it as easy to change out as the Solid rotor discs?  (unbolt the spindle/bracket from a later disc brake vehicle and bolt it up in place with rotors and calipers)  

3.  WHat is the best rear disc kit available for AMC 20 rears?  (at least I think it has an AMC 20... haven't checked that part out yet)

Thanks for your input

-- 
Frank Swygert
Publisher, "American Motors Cars" 
Magazine (AMC)
For all AMC enthusiasts
http://farna.home.att.net/AMC.html
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