Ford 8.8" in Kirkham 427

CaveMan · #1 (**permalink**) 12-09-2006, 12:31 AM

Since, once I have the wherewithal, I would only consider a Kirkham 427, I was wondering: can the Ford 8.8" differential be utilized in the Kirkham as a more cost-effective alternative to other offerings? I'm one of those folks where overall cost is an important factor, but I am not willing to compromise on quality (aka champagne diet, beer budget).

I noticed that when the Kirkhams were experimenting with fiberglass and offering "the 25k deal" they mentioned that their package would include a Ford 8.8" rear differential as they had been able to modify the frame to accept it; I know that they aren't pursuing the fiberglass body anymore, but I'm just curious to know if they would still offer the Ford differential in any of their current cars? (Mr. Kirkham, you should know that I am still a few years away from being able to seriously contemplate purchasing one of your cars, but I view your website often.)

Thank you

Clois Harlan · #2 (**permalink**) 12-09-2006, 10:11 AM

I have ran a 8.8 in my rear end of my 427 535 hp for over two years and absolutely never a problem. The 8.8 is a very durable option. Everyone that knows me knows that I like to "Jump on it" from time to time and then there are those infamous track days. In short I drive my Cobra the way it was suposed to be driven.

Some things I am very sure of and one is my Toploader and the other is my 8.8 Rearend, both are virtually indistructable.

Clois

ENTDOC · #3 (**permalink**) 12-09-2006, 11:40 AM

stick with a Jag diff,they are actually not that expensive,fit perfectly and more periond correct in a Kirkham. Why reinvent the wheel on these cars. Now for other applications the 8.8 is a good choice.

Three Peaks · #4 (**permalink**) 12-09-2006, 12:05 PM

I am installing a Ford 8.8 IRS in my scratch built CSX style chassis identical to the Kirkham chassis. It has required a substantial amount of fabrication of suspension pieces and mounting systems to make it all fit properly. I don't know how well it will work yet, since I don't have it on the road yet but I managed to stay fairly close to the original style suspension style and geometry.
A consideration also is that I don't know of any pin drive style hubs available yet for the 8.8 Ford rear end.
I imagine this isn't an option that Kirkham will be offering anytime soon as the Jag rear works so well in these cars as is. You aren't required to buy the rear differential from the Kirkhams, so a substantial savings may be had by shopping around for the proper Jag rear in used condition from a wrecked car of the proper year.
I believe also that most of the Kirkhams are set up for big blocks, so more fabrication will need to be made to accomodate a small block if you decide to go that route for money savings.

There are many good quality cars available for less money than the Kirkham that would be easier to accomodate your needs and your budget. You might try getting a ride in one or go to a gathering with several different Cobras in attendance and talk to the owners.

Just my 2 cent's worth- Bob

xlr8or · #5 (**permalink**) 12-09-2006, 12:26 PM

Cave man I don't think it's worth the effort. Kirkham already has the mounting hardware for the Jag setup and the Jag diff isn't but a couple hundred more than the 8.8. You would also need to have a custom set of half shafts made to fit the 8.8 on the inside and the Kirkham hubs on the outer. They use totally different half shaft designs so it would be difficult at best.
Three peaks has an advantage as he is scratch building and can put his own rear uprights in that will accept the Ford axles for the 8.8

ZOERA-SC7XX · #6 (**permalink**) 12-09-2006, 12:43 PM

Ditto...don't put a straight rear in a Kirkham or an ERA...you'd only be making more problems for yourself. There's plenty of good Cobras built with Ford rears...check them out.

Maricopa · #7 (**permalink**) 12-09-2006, 02:24 PM

I don't think anybody's talking about a straight axle, just the center section (usually from a T-bird). Both FFR and SPF use them for on their IRS set-ups.

Anthony · #8 (**permalink**) 12-09-2006, 04:15 PM

Quote:

Originally Posted by CaveMan

Since, once I have the wherewithal, I would only consider a Kirkham 427, I was wondering: can the Ford 8.8" differential be utilized in the Kirkham as a more cost-effective alternative to other offerings? I'm one of those folks where overall cost is an important factor, but I am not willing to compromise on quality (aka champagne diet, beer budget).

If cost is your concern, then why are you trying to customize something that is really not a problem?

Maricopa · #9 (**permalink**) 12-09-2006, 05:09 PM

I noticed that when the Kirkhams were experimenting with fiberglass and offering "the 25k deal" they mentioned that their package would include a Ford 8.8" rear differential as they had been able to modify the frame to accept it

He's not customizing it, supposedly it was made to work with one, and they just as strong and substantially cheaper.

xlr8or · #10 (**permalink**) 12-09-2006, 07:45 PM

The problem is the driveshaft yoke and the axle locations are different for the 8.8 IRS and the Jag setup so the entire rear frame area would need to be modified to accomodate it. Kirkham never had one setup that way. They were looking at doing it for the fiberglass car but never did the mod or sell a fiberglass car.

Anthony · #11 (**permalink**) 12-09-2006, 10:20 PM

Quote:

Originally Posted by Maricopa

I noticed that when the Kirkhams were experimenting with fiberglass and offering "the 25k deal" they mentioned that their package would include a Ford 8.8" rear differential as they had been able to modify the frame to accept it

He's not customizing it, supposedly it was made to work with one, and they just as strong and substantially cheaper.

Then buy the $25K Kirkham with the 8.8 rear.

Ant · #12 (**permalink**) 12-10-2006, 02:59 AM

My car is a Ram SC, and the design was endorsed by Shelby from 1992 to approx 2002, being an english car, is naturally setup for the Jaguar IRS, I have an alloy Ford 8.8" IRS that is being fitted to this chassis with all new axles and suspension arms, YES a lot of work!!!!!!!!
The reason is that in my opinion the Jag IRS is far to heavy, and in my last Cobra I kept screwing the Jaguar outer coarse 10 spline hub axles, yet quite a few people seem to run up to 800bhp with no problem.

So generally the Jaguar IRS is very good and as in a Cobra if you have the double wishbone like an original they work real well, and you can get moly outer axles etc for them. I am not that keen on the 8.8 IRS inner plunge joints, but we will see everyone says the Cobras weigh half the weight of the Thunderbird etc.

In the kits here in NZ, the Almac Cobra when racing on high speed air force bases the Jaguar diff can be unstable on high speed turn, a few guys have gone to Nissan 300ZX viscus diff with double wishbones, but you aint going to do that with a CSX or Kirkham, a much stronger diff than Jaguar or Ford 8.8" with a larger crown wheel etc!!

CaveMan · #13 (**permalink**) 12-11-2006, 10:11 PM

Thank you everyone for your input; as always, this forum produces a wealth of information. I hope that next time the Kirkhams offer a $25K cobra I'll be ready for it at that time (if that ever happens again.)

In case anyone is interested, my ideal build includes a big-block (just my personal preference

).

Thanks again