[Cobra Dude]

How much "room to grow" do you think you'll need? A 302 block is good to 450-500 safe hp, and even more with a bottom-end girdle. And that's not even an A4 or R302 block -- I'm referring to a street 2-bolt mains block.

To get there, you can make a good streetable 400hp N/A, but you'll lose low-end smoothness if you open it up more (still N/A). Supercharging or turbocharging (probably not too easy in a Cobra) will give you everything you need streetably.

That's where the 351W shines -- you can do more hp with a smooth idle. But yes, it'll add some weight.

I still feel that overall, 302 mods are far more readily available than 351, but that's not from any scientific data. If you'll stay carbureted, then perhaps the 351 is the way to go.

I started life with a 302 thinking it'll be all I need in such a light car, but 8 years later I have 500+ hp on the same 302. A rebuild last year told me that I did not need a rebuild, but I took the opportunity to beef it up somewhat with a girdle, etc.

Cheers,
-Neil.