Engine size?

[SteelCobra]

So along with the rest of the posts, think about resale. Look at Cobra Country..., and find like manufacturers and years, and then look at the price of the big blocks vs small blocks. I had the same question last year, and found that no matter the manufacturer, the big blocks retain their value over the small blocks. They are thirsty, but the sound and power will keep a smile on your face. You may want to reach out to one of the local clubs in your area, and see if you can catch a ride and/or some advise one on one from the owners. No matter what the decision, they're not for the faint of heart! Good luck!

[Ace23]

The most important thing is to be honest with yourself on what your expectation of fast and powerful is. I am a younger cobra enthusiast and have owned my car for 3 years this March. I’ve had a 600rwhp 03 cobra and a 600hp turbo charged Hayabusa in the past. My car just went through a year long overhaul in which a great friend of mine completely reworked my 427 Windsor and performed a 6-speed T56 swap with 4.30 rear gear.

My previous setup was around 580HP and 575TQ and I should be around the same now....it is absolutely fast but could I use more....of course. If you like roll on power just go with the 385 series big block and have someone like Brent Lykins build you a streetable setup that runs a hydraulic roller. Personally I think this will be the next project for my car. I think 750hp and 700tq is what I would be going for. You are going to have all kinds of opinions about what makes a good cobra but you need to go with your gut on what will be fast for you. Having more cubic inches and more power than you can use is better than not having enough....these cars have gas pedals so it can be controlled.

My other option would be a 460ci clevlor style Windsor but I think it would not be as streetable. You can make crazy power with Windsor platforms but That may come with running a solid roller etc.

[MKS427]

There are many ways an engine can perform, low end torque or high end power. You really need to define your driving or racing parameters to make a decision.
If you are going road racing, a Coyote with a dry sump may be best. Not enough horsepower, supercharge it.
I personally run a 351W based 427 Dart, 572hp/585tq. It has a hydraulic cam, performer rpm manifold and is very streetable with EFI. Now that I have 6000 miles on the car, I am getting comfortable with the power and would welcome more. Keep in mind, even with 100 series tires, losing traction is effortless below 60.
I like the sound of the 500+ inch FEs, best. They are pricey and I cannot speak to their performance first hand.
Good luck,
Mark

[520SC]

I run a relatively tame 502 (a 460 block with a 4.39" bore and a 4.15" crankshaft, 225/235 degree hydraulic camshaft, 9.5:1 compression). It makes 515 hp at 5200 rpm and 585 ft-lbs at 4200 rpm. During the summer months, it runs pretty hot in heavy traffic, about 220F. I really like the wide power band and the sound of the engine, but granted, it's not a traditional setup by any means (e.g., not an FE engine). It's not true to the Cobra heritage.

[cycleguy55]

Originally Posted by 520SC

I run a relatively tame 502 (a 460 block with a 4.39" bore and a 4.15" crankshaft, 225/235 degree hydraulic camshaft, 9.5:1 compression). It makes 515 hp at 5200 rpm and 585 ft-lbs at 4200 rpm. During the summer months, it runs pretty hot in heavy traffic, about 220F. I really like the wide power band and the sound of the engine, but granted, it's not a traditional setup by any means (e.g., not an FE engine). It's not true to the Cobra heritage.

OTOH, if shelby was still building Cobras in the '70s and '80s he'd likely have been using 385 Series engines - unless he stopped using Ford engines.