ERA 427 WHEEL SIZES AND OFFSETS

Tire Selections Here

Over the years, we've put many different size wheels on our 427.  The table below shows what we have determined to fit correctly with the tire size indicated.  I can supply supply the wheel manufacturer with more pin-drive and bolt-on wheel hub dimensions on request.  

For machining reference, basic drawings of the front and rear Pin-drive hubs are here.

FRONT (Pin-drive and bolt-on wheel spec's are the same)

Tire Size
Wheel Size
Backspacing (See below for measuring)
235-60-15
7"W x 15"
3.2"
235-60-15 7.5"W x 15"
3.4"
265-50-15 7.5"W x 15" 3.7"
265-50-15
8.0"W x 15"
3.9"
275-50-15
8.0"W x 15"
4.4"
275-50-15
8.5"W x 15"
4.6"
275-40-178.0"W x 17"4.25"
275-40-17 8.5"W x 17" 4.5" 
275-40-17 9.0"W x 17" 4.75"
Note!  You must maintain at least 0.8" clearance for the optional 4-piston front calipers.  See the picture below.

REAR (Jaguar (bolt-on and pin-drive) and
ERA rear suspension
, pin-drive

Tire Size
Wheel Size
Backspacing (See below for measuring)
235-60-15
7.5"W x 15"
3.25"  Used with Sunburst wheels, we use especially lengthened lower control arms.  Inquire
295-50-15
9.5"W x 15"
3.5"
305-50-15
9.5" W x 15"
3.6" *Note: Tire fit is tight before chassis 731, improbable before chassis 350
285-40-17
10.0" W x 17"
3.6"
315-35-17
10.5" W x 17"
4.0"
315-35-17 11.0" W x 17" 4.3"
335-35-17 11.5" W x 17" 4.7"

REAR (ERA rear suspension, bolt-on

Tire Size
Wheel Size
Backspacing (See below for measuring)
295-50-15
9.5"W x 15"
3.8"
305-50-15
9.5" W x 15"
3.9" *Note: Tire fit is tight before chassis 731, improbable before chassis 350
285-40-17
10.0" W x 17"
3.9"
315-35-17
10.5" W x 17"
4.3"
315-35-17 11.0" W x 17" 4.6"
335-35-17 11.5" W x 17" 5.0"

Larger diameter and wider wheels can be fit withing certain design parameters.  See here for bolt-on wheel hub specifications.  If you need help with this, please e-mail us* with the intended diameter, width and tire sizes.  

*This service is only for ERA owners. 
(Tire Size Calculator)
Directly below is a typical front pin-drive wheel with the normal requirements illustrated.

FRONT

(Outside surface to the right)

PDF Drawing for printing

Front wheel offset dimensions

If the back side of the wheel is machined, make sure that the drive pin hole depth is maintained.

SAFETY WIRING

We strongly recommend that you safety wire the wing nuts.  We like to keep the finished wire snug.  Some leave a little slack so that if the wing nut moves, the wire slack will show a difference.  More safety wiring hints here.
Procedure:
Drill a 1/8" hole in the wingnut. See below for location.  Some like to drill a hole in each of the wings to make it easier to get an ideal angle-pull.
Loop a length of wire around a wheel spoke. Make it longer than you think you need. You can trim the extra length later.  Wire so that the wing nut is being tightened!  The right hand threaded wing nut is on the left (driver's) side.  The passenger's side wing nuts are left hand thread.
In other words, tighten the wing nuts in the opposite direction of forward wheel rotation.
Clamp the pair of wires with the pliers where you expect to end the first twist section. Don't get too generous initially - you can add more length if necessary.  

Slide the central sleeve down on the pliers to retain the "clamp".

Pull the knob at the end of the pliers.  Twist the wires to within 1/4" of the wing nut connection, no more than 6-8 turns per inch.  Twist with no more

Twisting the wire, 1
Loop one leg of the wire through the hole in the wing nut and clamp the pair of wires as before.  Twist about an inch of wire. Next loop
Clip the excess wire from the twist and bend out of the way. Finished, almost