Defend the 10 bolt 8.5 rearend

T

tuggy24g

Member
Joined
May 9, 2009
I was over at Maliburacing.com and I saw a post that said 8.5 or 9". Well I wanted to see what people were talking about and what the poster wanted to know. So I opened it up and the guy just wanted to know if he should use an 8.5 or a ford 9".Also he has around 525HP. So everyone on the forum is saying go with a 9" except one guy. SO we need to step up and support the 8.5 in rearend. I have one in my 86 El Camino and I support it more then an 9". I think it can be just as good as a 9" if built right and done a lot cheaper!Check it out for your self too
MalibuRacing.com Message Boards • View topic - 8.5 or 9"
 
OC Cantrell

My little buddy is in the high 8's with a 8.5 built my himself.
 
Nah... some of those boards have a lot of close-minded people on them. My chevy friends that know their stuff laugh at the stuff they read on there.
 
The 8.5 is great ... but it gets linked into the same category as the newer 10 bolts which really suck ---
 
I wish people like us could teach other car guys about the 8.5 and tell them that you can build an 8.5 to handle tons of power. Also to do so can be much cheaper then a ford 9". That was the key and thanks to all of you I decided to stick with an 8.5 :)
 
you can lead a horse to water but ya can't make them drink :p I had guys ask me all sorts of stuff. Ill tell em my opinion and they do the opposite :biggrin: So if they "NEED" a 9" let em :cool: who cares ??
 
For 525hp who cares:rolleyes:. A 7.625" would probably last a while in there. 8.5" is plenty for 99.9% of what you will ever see on the street. Reliability of the 8.5" is limited in full weight cars that are capable of 8 sec passes and 525hp isnt going to get you anywhere near there. Its cheaper to sell your known good 8.5" and buy a built 9" if your planning on going that fast. I see a lot of guys throwing $1000+ at their 8.5". They could have just sold it as a stock unit for $850 and invested in a bad ass 9" for about $600 more total investment. Depends on the goals. I would not run a 8.5" in a fast drag radial car regardless of weight. Tire shake is a rear killer
 
Malibu;s

The other thing to remember is the 8.5 is about 3-6% more efficient.In stock eliminator when every .001 counts the 8.5 is highly favoured.:rolleyes:I have found the Malibu /SS guys replace alot of parts with so called go fast goodies and go slower and slower with every change ie 1000 cfm carbs,huge cams and way too much gear and converter.:eek:To each his own but if people dynoed half the stuff the local speed shop sold they would not sell too much :rolleyes:.Just saying

Kevin
 
That is a good point. The 9" take a little bit more HP to make it work then an 8.5 so your going to loose a second of two. So That is why I went with a 8.5" over a 9". Every little HP I can save and use for power that is what I want to do. If I have to take away some just bc of a rearend I rather not.
 
SS/GN said:
The other thing to remember is the 8.5 is about 3-6% more efficient.In stock eliminator when every .001 counts the 8.5 is highly favoured.:rolleyes:I have found the Malibu /SS guys replace alot of parts with so called go fast goodies and go slower and slower with every change ie 1000 cfm carbs,huge cams and way too much gear and converter.:eek:To each his own but if people dynoed half the stuff the local speed shop sold they would not sell too much :rolleyes:.Just saying

Kevin
Click to expand...

I agree with this in stock eliminator cars that already have several different converters which are changed out multiple times to nail down every bit of e.t. but on a street driven car that likely has a converter that is a far cry from what is really efficient and many other power robbing issues a rear thats going to eat up about 6 or 7hp in a 600hp car should not be much of a concern. The Malibu guys i know of are flying in their street race cars. A couple have the 8.5" and most are 9" cars. All of them run N2O small blocks and make huge power. Enough to push the cars to well over 150mph in the quarter.
 
Well the problem I have with some of them is that they do not think before they talk. They say stupid thing and yet they do not know what they are talknig about. They bash the 8.5 rearends and yet they really do not know anything about them. I love my 8.5 and would not go with a 9" unless the price was a little cheaper. I payed probbley 1700 for my complete rearend and some extra parts I bought after. A ford 9" cost 2900 so I saved 1200 plus I know that my 8.5" will not break on me at all. SO I am vary happy wit how thing will turn out.
 
Well if you already have the 8.5 it's a different ball game vs. Paying several hundred dollars for a used gbody 8.5 and then having to go through it. C clips suck at any power level IMO and if I didn't already have an 8.5 in my car I damn sure would not waste time and money trying to find one. One of the car magazines recently tested the 12 bolt vs. the 9 inch vs. The Dana 60 in a decent power car on a dyno and found no measureable difference. Very few people are running stock elim. anyway and most of the rest are throwing away more power in other areas than what a 9 inch wastes 'in theory'.

Just my opinion of course.

When was the last time you saw a 9 inch axle break that ruined a quarter panel?
 
the 8.5 is good if you already have one, but since i stumbled across a place that makes a complete bolt in full floater housing that comes with hubs, axles (30 or 33 spline), and brake rotors for $699- just add a center section with whatever gears and differential you want and some brake calipers and you are ready to roll- i think a 9" would be the way to go if you don't already have an 8.5 and don't want to worry about a broken axle causing a wheel to fly off..
 
Well I think for me it was cost. I spent a good bit of time looking for an 8.5 and found one close by and it was a heck of a deal. I am happy with the results!!! Now I just need to put the finishing touches on it and I will be ready to roll. Like I said I saved 1200 and I know I can drag race the crap out of my car and not break my rearend or axles at all.
 
my 8.5 has ford ends [large bearings] 33 spline axles moser spool, i have never broke a ring&pinion, i have been 130 sixty foot, but if and when i break it i probably will go with a 9 inch,
cal hartline went 8.50 in a 3400 lbs car with a 8.5
everone has an opinion and choice.
other side i have 2 extra ring&pinions
good luck, oc,
 
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