Class Question

[MustangRacer]

I want to know if I can run in the ESP class, I am clarifying if is ok to increase displacement of your engine and swap out the original Solid axle for an IRS, as well as upgrade to larger brakes over stock w/ braided hoses.

[michael smith]

S. Cylinders may be rebored to no more than 0.0472 in. over standard
bore and the appropriate standard oversize piston may be substituted.
This overbore dimension is an absolute limit; no additional tolerance
is permitted to accommodate wear.

Was there a larger engine other than the 4.6 included in the following?
Mustang (S197 chassis) (2005-09)

[MustangRacer]

Mine came with the 5.0L OHV engine, they didn't come out with the 4.6L engine until the next year, they did have a 5.8L Cobra R the same year as my car. and I am looking at the stroker kits, and it is only a .030 larger than stock. but I did use different style pistons, mine are notched for clearance of my valves.

[MustangRacer]

Ok, I read farther into the rule book and I am pretty sure I am in SM due to me having aftermarket heads and an aftermarket cam.

[woodrufj]

Yeah a stroker kit it beyond ESP prep. The allowance that Michael is quoting is a standard rebuild, not a 'gain performance' kind of allowance.

For the most part, Street prep is bolt on suspension mods, any wheels and tires.

Street Mod is where you get into engine allowances.

Jay W

[MustangRacer]

Oh ok, that makes sense, thanks for the clarification.