Looking for rear end opinions

[parsonsj]

Have you ever done an 8.8 in a g body?

Does almost count? Sorry -- I was talking with somebody about doing one, but he ended up going with used parts; I don't know how it turned out. I've done a few with DSE Q-Links, which is quite similar. You'd need to find custom brackets to weld to the housing for the links.

[1985olds]

I was going to use this kit

https://trickchassis.com/index.php?i...oller=category

I just worry this is a band aid and not a solution.

[1985olds]

Has anyone used this kit or have any issues with it?

[BonzoHansen]

OK so dumb question of the day why use an 8.8 and not find factory 8.5 housing and build that? You can build a pretty stout 85.

[parsonsj]

I like the 8.8 because you can get everything you need brand new from Ford. I'm not sure that's possible with an 8.5, but I am prepared to learn something.

[1985olds]

OK so dumb question of the day why use an 8.8 and not find factory 8.5 housing and build that? You can build a pretty stout 85.

8.8 is said to be strong than the 8.5, though in sure some will disagree. With the 8.8 i can use Ford 9" ends and axles so I don't have to worry about losing an axle. I paid $100 for a fox body 8.8 vs. a stock 8.5 which range from $1000-1500. I'll only be a few hundred more into an 8.8 with aftermarket axles, diff, gears, new bearings and gaskets, labor of setup and supporting install parts

[CSG]

The Ford 8.8 is quite strong with good axles. Good brakes are easy to find and cheap. 9" end conversions are an affordable upgrade.

[BonzoHansen]

8.8 is said to be strong than the 8.5, though in sure some will disagree. With the 8.8 i can use Ford 9" ends and axles so I don't have to worry about losing an axle. I paid $100 for a fox body 8.8 vs. a stock 8.5 which range from $1000-1500. I'll only be a few hundred more into an 8.8 with aftermarket axles, diff, gears, new bearings and gaskets, labor of setup and supporting install parts

I didn't realize g body 8.5s were that much. F body housings are like $100. So yea that makes a lot of sense.

[Ben@SpeedTech]

Hey 85olds- I had the same question, I had a 325 hp/ 400 ft lbs sbc 406 and was lucky enough to find a stock GN 3.42 8.5" to put in my Cutlass wagon. Now I'm installing a new roughly 550 hp/ 525 ft lb sbc 406 and although I've read a 10 bolt can handle 500 hp ok I don't want to take any chances. I thought about the 8.8 swap and some guys on G-body forums have said it's relatively easy. Cost isn't bad since for a Pro-Tour build you'll be buying new rear control arms anyway. I think UMI has offset uppers for the 8.8 conversion and the lowers are supposed to be a bolt-in with any G-body arms.

After doing a bunch of research, I ended up choosing a 9" instead, I think the advantages out weigh the disadvantages. I found a trac loc rear in a '78 Bronco in the wrecking yard for $125. It's a lot longer than a G-body rear so I have to narrow it and buy new axles and may change the gears but even with that I'm still cheaper than ordering a new rear. Best I can tell is many Ford truck 9"s come with 3.50 gears, just about perfect for a P-T build, and they have the larger bearings and 31 spline axles. Factory gears will whine less than aftermarket.

The parasitic loss- Would I really miss a few hp on the street or autoX? No. Maybe if I were drag racing and trying to get another 1/2 of a 10th out of it but you'll never see that level of power loss factor in while autoXing. You can knock .005 seconds off your autoX time by saving a little hp loss, or simply become a better driver and knock 2 full seconds off your time. Make sense?

The extra weight- How much heavier is it anyway? I've heard 9" are lighter than 12 bolts but I can't confirm that from personal experience. I can't help but think a 9" isn't that much heavier than an 8.8. A car with 50-50 weight bias is a good thing for handling, so adding a few lbs out back may help with that anyway. From my observance G-bodies with pro touring suspensions like to lean towards oversteer until you get it tuned out, plus you've got a good amount of power so a few extra lbs over the rear tires to help with traction may not hurt either.

Strength- It should be safe to say the 9" is stronger, so if I decide a 150 shot of the bottle or a 700+ hp boosted LS may be in the car down the road I don't have to swap rears again.

Versatiliy- I plan to drag race my car with slicks on occasion (here's where the 150 shot comes in). I can grab another 9" center from the junkyard, install a mini spool and 4.56 gears and in an hour I have a drag race rear swap. Brake options for a 9" are wide open and super common, from 11" drums to 14" 6 piston discs.

Adjustability- I bought my control arm brackets from Speedway Motors which gives me several mount holes for lower arm adjustability and the top ears will be welded on in stock G-Body locations. I think you can get these multi hole brackets from any good axle builder if you buy a complete new housing. Since my car is already set up I can keep my Speedtech Articulink control arms that I'm very fond of.

Fit- You mentioned welding new ends on, which means you can narrow a Mustang rear, but if you were to use the Mustang rear "as is" like most swaps have been you have to use high offset wheels. G-bodies look good with deep wheels, so with the 9" I can have any offset I want. My current wheels have 4.5" deep lip, I like this much better than the Corvette offset look on the rear of old cars.

Cost- As mentioned with the Bronco axle I'll come out ahead of buying a complete new rear. A new pre-fab 9" is a bit more spendy. In the scheme of things the extra $ might be worth the extra insurance of having the confidence in knowing it'll probably never break despite any abuse you throw at it. You're already doing all the same work to the 8.8 to bring it up to 9" axle, end, brake etc. standards, why not just get the 9" and be done?

Look- I suppose there's some cool factor when people look under the car and see a 9". Everyone will know your car is serious and just saying it's a 9" conversion adds resale value to the car. The 8.8 will blend in and to the untrained eye they may think it's just a GM rear.

Hope this gives you some things to think about so you can weigh the options and make the best decision for you and your budget. Good luck with the build!

[1985olds]

Thank you for the response. You have me reevaluating my plans once again. You bring up a lot of good points. You said you picked up a bronco rear, will that center section housing stand up to the abuse? From what I found during my research the stock center housing is only good to about 425-450. If that is not the case that would make my decision easier. The major expense is not the rear end housing itself but the center section. A fab rear housing with axles/bearings from quick performance is only about $950. As far as brakes going I will be sticking with my 1995 corvette brakes as the parking brake is already set up and I like the performance out of them.

[Ben@SpeedTech]

Hmmm, I've never run across that hp limitation but will research it more too to be safe. What have you come up with for the 8.8's limitation? Aftermarket centers can get real spendy. If the factory 9 won't handle the power, then maybe the 8.8 is the best route for a budget build, the 9 if the coin isn't an issue. I guess we both have some more research and thinking to do, lol! When the dust settles in the end I personally still like the advantages of the 9" better.

[Zachalanche]

if you build an 8.8 right (including c clip eliminators), the only advantage that the 9 in has is the better supported pinion, and increased tooth contact area. which would be preferable for really hard launches, but unnecessary for most everything else. the advantage of the 8.8 with its slightly reduced tooth contact area is less parasitic loss. The 8.8s are also lighter (unless you compare to an aluminum 9 in 3rd member, then I don't know).

I run a 9 in because I have an old mustang that came with it. but had it been an 8in, I would have probably upgraded to the 8.8.

[1985olds]

I may be wrong about the 9" limitations, i read that awhile ago. I haven't found a solid number for the 8.8, but most will say a lot or more than most people will put through it. There are a lot of reports of people running 8's with them. I'm not looking for 8's or all of the horsepower, I know the 550-600 I'm looking to run will probably be the most I run. I drive The car everyday in The summer and am not willing to cross that full fledged racecar line. The problem I'm having is both rears will cost about the same at the end of the day and both have their merits.