I have a 76 maverick that had a factory I6 250. I am putting a 302 stroked to a 347, with aluminum heads, and some other stuff. I was wanting to know what size rear axle is in it. And what does it mean when the original sales paper say it has a factory heavy duty package in it? Also will the rear axle that is in the car handle 350-450 HP??? all info would be great, Thanks
unless it was changed the rear end is an 8". it should hold if you don't abuse the haeck out of it. however, you might not be happy with the 2.79 or 3.00 gears in it. a good 8" is okay for about 450hp. but remember that's one that is in good condition.
It's an 8 inch. Look on the sticker inside your door jam. It will say Axel: the number 3 means it's a 2.79 and the number 6 there means it's a 3.00 gear.
The 8" is a pretty tough unit. If you are running an automatic, that would be even better for it. Manual gear boxes are a little tougher on the driveline components. The heavy duty package you refer to would have given you heavy duty springs and shocks and possibly a heavier sway bar . Nothing beefier about any other components like the rear end or frame.
thanks for all the help, i also was wandering if it would be werth Posi track and putting in new ring and pinion? also what would be a good ring and pinion to go with like 3:55, 3:73, 4:10 ????
3.55 is pretty good for strip, and still decent on highway. 3.80 is better for strip, but starts to be hard on highway (3000rpm@55mph). 4.11 is great for strip, but I wouldn't do highway at all with it.
I would use 3.55 I know of one that has a prity built 302 straped to it. that car catches a lot of abuse and it has held to any thing we could put it through
Personally, I would go more of the 3.80, unless this is a car that sees daily highway driving, then I would do 3.55. I drive highway maybe 2-3 times per month for maybe 30-50 miles. I have a 3.80 (with a spool posi) and I tend to keep the rpms right at 3000-3500 which puts me at 60-65 mph...a little slower than the rest of the traffic, but getting along pretty nicely. I don't drive on days that I have to go into Houston where I would become a road hazard or hold up traffic. I only drive to work on "leisurely" days. The 3.80 jumps off the line much quicker than 3.55, and WAY quicker than 3.00 or 2.79.
I have slaughtered three 8" rears... They all broke without issue to the u-joints or driveshaft. Believe it or not, the u-joints and driveshaft take a lot to break compared to the rear end. Remember, the rear end goes through the process of torque multiplication. When the driveshaft sees a certain level of power, the differential sees 3.55 times as much, or 4.11 times as much, etc... I don't trust 8" anymore. My .02 Dave
I have yet to break my 8". Mini spooling it helped a whole bunch. Lots of one wheel burnouts with a lot of power are very tough on a differential. In my little Courier I actally shot half of a spider gear right out of the back of the housing. What a mess...
That must have been my problem. I was king of the peg-leg burnout! One thing I especially loved was when you romp it, the tire broke loose instantly, so the car just barely moved forward... Now bring it up to about 6k rpms. Then when I let out of the throttle, the tires would hook at a very low (walking) speed, and the car would lurch forward with whiplash force and bring the engine back to idle. Very pro-stock sounding and looking from the outside on the passenger side of the car. Probably looked like the dorkiest thing ever to the driver side onlooker. Dave
hehehe. That was my normal routine in the Courier until I figured out how to get both tires going by yanking the wheel back and fourth for a second. They were both spinning when the spider gear shot out the back.
My 8" w/3.55 & mini spool lived running 7.80/12.40 times,hitting 150 NOS off the line on G-60 M&H's for about 6 years before I warped the axle tube on the right side.
