[Jack21]

L 0.02

For mostly street use, you don't have to get particularly wild on aftermarket parts. A stock displacement 429 is plenty. A stock torque converter, even an aftermarket one, is plenty. Stall speed should be 1400 - 1800 RPM. You want a stock passenger car to RV (recreational vehicle or SUV) stall speed on this. Go with a 2500 - 3000 RPM stall speed will get you excessive heat, excessive wheelspin, a slower car, and horrible fuel ecomomy.

Remember, you have an extremely light car with a large engine. Making torque isn't a problem. Propelling the car with the available torque is the problem. You want the fattest rubber on the rear wheels as you can get, and a rear suspension that will let you "Hook it up" to the extent possible.

In the U.S., the faster cars are running 302's, or stroker 302's (331 - 347) with superchargers.

Consider a retrofit hydraulic roller cam and roller rocker arms before going with strokers to optimize what you already have. Keep the duration conservative for street use. 218 - 224I, 224 - 234E for a mostly street use cam will give you a rumpeta-rumpeta idle, and 15" vacuum at idle. 6200 RPM will be the max RPM for this engine, with this cam. No exotica is needed on the bottom end to achieve this.

A Holley, or Demon 750 is the right size carb for this engine. With automatic trans, vacuum secondaries will work fine. For street use go undersize (750cfm) rather than oversize (850) on the carb. Snappier throttle response.

Where you are, U.K., your only competition is another Cobra. Granted, you'll ocasionally run into a turbo Porsche which with your roller 429 you'll easily eat for breakfast (up to around 130 MPH); you don't have Vipers or Vettes to deal with. So count your blessings, build your ultimate muscle car, and rest assured that damn few (if any) will kick (or attempt to kick) sand in your face.