427 Rear End Width

Gman1013 · #1 (**permalink**) 12-31-2003, 08:15 PM

Waht should the rear end width from rotor to rotor be for a 427 Cobra? I have a Shell Valley and I think the rear end is too wode, atually, I know it is. Not sure how much more it van be narroxed and still have all the necessary hardware and mounting brakets retained. I have knock off adapters and knock off wheels that put the tires at least 1-2 inches outside the wheel well lip. Looks ugly and is ruining my new tires. I was told the Trigo Knock-off wheels only come in one offset for the rears which are 9.5" wide. I would hate to have to pay for new wheels since they arent too cheap although naroowing the rear even more won't be cheap either.

Thanks,

Greg

decooney · #2 (**permalink**) 12-31-2003, 09:06 PM

The final dimension also depends on the width of your body iteself. You can rub on the inside if you go too narrow and rub on the outside if you go too wide. I narrowed my Unique/IRS Jag 427 Cobra rear to 52.5" and my ERA IRS 427 rear built to spec at 52.5". Both cars run Trigo wheels with 5 pin adapter hubs. Good luck. I recommend lots of measuring, remeasuring and mock-ups with the car sitting/loaded to be certain about what to narrow it to for your tire width and body type.

Gman1013 · #3 (**permalink**) 12-31-2003, 09:49 PM

thanks for the measurements and advice. Right now mie measures about 55 1/2" so 52 1/2 sounds pretty close.

Happy New Year!!

Gman

Cameron Parsons · #4 (**permalink**) 01-09-2004, 03:00 AM

I would be interested to know if you needed to make any serious adjsutments to the suspension setup and if the narrower rear was compensated for with the bigger rubber? (assuming that was why you narrowed it?).

I have a Jag IRS and would like to run Trigo's also. How difficult was the narrowing process??

Thanks

Clois Harlan · #5 (**permalink**) 01-09-2004, 06:01 AM

Duane,

Are you measuring from the inside of your rear rotors? Because if you are a standard Ford Explorer 8.8 rearend will fit. I think they measure 52" inside to inside rotor. On a IRS I have been told that the 86 Turbo Coupe is one of the most narrow units available.

Mine measured 52" and needed to be cut down to about 48".

Clois

decooney · #6 (**permalink**) 01-09-2004, 09:01 AM

I'm measuring from outside hub to hub (right where the wheel mounts flush). Also, remember, the 52.5" wide compensates for the added Trigo adapters, will push the Trigos out almost another 1/2 inch.

Narrowing is not fun on a Jag rear, and its time consuming. I did part of mine and let ERA handle the axles this time. If you have not done this before, it takes someone with the right jig and measuring tools to make sure your parts get welded back together straight/square, etc. Also, the axles need to be put back together correctly to make them safe. Unique, ERA and others reputable builders do this all the time. You might want to speak with them if you are serious about trying it on a Jag IRS.

Cameron Parsons · #7 (**permalink**) 01-09-2004, 01:33 PM

For comparison, as I will be working on a DAX (english) car. Do you know your body measurement from inside the rear aurd lip, side to side on your car?

Thanks for the tip on the rear end... I have been considering one of the re-engineered reaplcement rears as I am a little paranoid about suspension failure at high speed, so I may just go with a purpose built replacement. If not I will definitiely employ a specialist.