CHOOSING TIRES...

is always an interesting challenge.  The best sizes (that match the original cars' profiles) do not offer many high-performance choices.  With 15" wheels (7.5" and 9.5" wide), we recommend:

Front*: 235/60-15 (If you can't find 235s, 245/60-15 will fit the 427 after chassis 731)

*Avon tires seem to be sized a little differently.  Use 225/65-15 instead.  See below for M/T sizes.

Rear: 295/50-15 (rim width 9" or more), 275/55-15 (rim width less than 9")

Other possible sizes (including 16" and 17" rims) are listed here.

• Chart for determining tire outside diameter vs section, width and wheel diameter
• Information on tires, sizes, and adhesion

Some Tire Sources

• Tire Rack
• Performance Plus
• 1010 Tires
• Sasco Sports (Avon)
• Jegs, Summit (M-T)
  

Technical information

• Sizes, speed ratings, etc. from 1010 Tire

Tires that (may be) available in both sizes, as of 06/11/24: Some may be be a bit scarce.

Wheel Sizes For: 427 -------  FIA

Speed Ratings

In the USA, since you will never excede the legal speed limit, speed ratings shouldn't be a primary factor in tire choice.  But, it's nice to have a little safety factor anyway.  As you search through the tire distributors' offerings, you will find that only Avon and M/T (S/R only) tires have a higher-than-T speed rating. 

Currently the available brands that (may) offer both sizes include

• Avon FIA Rally CR6ZZ DOT (V-rated)
• BF Goodrich Radial T/A
• Firestone Firehawk Indy 500
• Goodyear Eagle GT II
• Mickey Thompson S/T 
• Mickey Thompson S/R, sizes 26x10.00R15LT (#6653) and 26X12.00R15LT (#6654) (speed-rated H)
  

There may be others, so it never hurts to search around.

Speed ratings

• S = 112 MPH, 180km/h
• T = 118 MPH, 190km/h
• U = 124 MPH, 200km/h
• H = 130 MPH, 210km/h
• V = 149 MPH, 240km/h
• Z = 149 MPH, 240km/h and over
• W = 168 MPH, 270km/h
• Y = 186 MPH, 300km/h