Joined: Fri Apr 21 2006, 07:28AM
Location: England
Posts: 739
What is the most desirable axle that was available on our cars? Presumably the strongest. I appear to have a 8 1/4. How does that compare. Can anyone put them in order, strongest first?
Joined: Sat Aug 19 2006, 05:03PM
Location: Ontario, Canada
Posts: 2919
Since the Dana 60 wasn't installed in any C-bodies (to my knowledge), that would be the 8 3/4. Arguably either the 489 or 742 case are the best. The 741 case is the weakest. However, I was told that, if you're running street tires and not slicks, you'll start spinning the tires before you'll ever hurt a 741 case.
Joined: Sat Apr 04 2009, 10:33PM
Location: washington
Posts: 163
I broke a yoke on my 489 case with crappy bfg street tires. The driveshaft then smashed the corner of my muffler on my tti exhaust. I upgraded to a billet 1350 size yoke and a 089 wall drive shaft and now even with cal tracs and drag radials have no problems. If i do break it i will find a dana 60 and make it work under there.
Joined: Sat Mar 29 2008, 03:36PM
Location: North eastern Wis.
Posts: 1638
What kind of horse power are you aiming at? The 8 1/4 is under everything from B body on up, including all sorts of trucks up to the 3/4 ton range and holds up just fine.
Joined: Fri Mar 13 2009, 11:21AM
Location: San Marcos, CA
Posts: 713
If memory serves, there was a Dana in C bodies with a 4 speed and 440 in the late '60s. I saw one at cruise for the cure in Orange county Ca. I ran a 3.23 742 8 3/4 behind a stout 440 / 727 in my '69 RR 6bbl clone on slicks. 4000 pound car with 11 x 32-15 racemasters. It ran 13.05 at 104, the rear end held up fine... back in the day, the '68 race HEMI darts ran an 8 3/4 behind the 727 from the factory. I don't know how stout the 8 1/4 is though. My $.02
What kind of horse power are you aiming at? The 8 1/4 is under everything from B body on up, including all sorts of trucks up to the 3/4 ton range and holds up just fine.
I dont think any 3/4 trucks got a 8 1/4. For awhile they used 8 3/4 and then for a while 8 1/4 on light duty half tons, then they started using 9 1/4s.
To the OP, the 8 3/4 is a very good rear end, every bit as strong as the ford 9" when compared apples to apples IMHO. They were used in the slingshot dragsters behind blown Hemis
Joined: Fri Apr 21 2006, 07:28AM
Location: England
Posts: 739
Art Im just doing a bit of research for the future. I have a 71 sport Fury with a 76 400i. Mild comp cam, edelbroke inlet, holley 750. I was hoping to build a stroker one day but I have so little time any engine rebuilding will done by the local molar guru. A brief talk with him tells me that the stroker parts plus labour is going to be too expensive. So what are my options for rebuilding the 400? He tells me piston choice is limited. What HP increase can I expect to get from the 400 and what will it need in terms of parts. I know the best option is to go for a 440. The problem is since I'm in the UK its a lot harder to get stuff at a reasonable price. You often have to make do with what you've got.
There are some good pistons for the 400, I have a set of KBs sitting on a shelf waiting for my 400. Cant remember the specs off hand but Im thinking theyre around 9.5:1 depending on how much youve surfaced the deck.
OR you could find a 440 crank (preferably forged) and build a 451 stroker motor on the cheap, IIRC you can use factory rods.
Joined: Fri Apr 21 2006, 07:28AM
Location: England
Posts: 739
I still like the idea of a stroker since most of the time the car will be on the street so torque is the way to go. But it looks like the cost of machining will add to much to the overall price if I'm having someone else do the build.
I have very limited experience with performance mods so I'm just looking for advice and opinions with what would be the best way to go with the 400 I have.
If I were to stick to a rebuild of my 400, what options do I have and what gains can I make. Im trying to learn as much as I can before I quiz my engine builder so I don't sound to thick lol.
Joined: Thu Oct 07 2010, 12:01PM
Location: vermont
Posts: 180
If your cylinder bores are good and you don't need it over bored that saves a lot of coin, some of the stroker kits don't require a lot of machine work just attention to detail. There are lot more 400 Pistons available now than 5-10 years ago, spend some(more!) time checking out the stroker web sites, I'm also working on a 400 stroker project but I have some other motors to temporize things but can appreciate your across the pond dilemmas. if there is something that can be carried as luggage, I' m happy to jump on a plane with a little bit notice, the pound being what it is, but stuffing a stroker crank down my pants is probably a thing of the past😋 cheers!