Supercharger vs. N/A build!

[olddog]

I agree that those heads on a 302 is not likely to give a true 400hp. Be aware that talk is a way to make huge Hp for very little cost, with little effort. So when you hear what the Mustang guys are doing, remember the Bull Chit factor on the HP. They may be about 100 hp less than what they say. Also not too many tell you that their engine only lasted 10,000 miles after their big hp modifications. Often times much less.

Also all dyno tests are corrected to what the engine should make at sea level. At 5000 feet you are going to be missing a lot of power. We just pulled a camper to Yellowstone with a new Ford F350 diesel. The power loss at high altitudes is huge. So I understand your situation.

500 hp at the crank on an engine dyno, will be lucky to get 400 hp to the wheels. Exhaust, air cleaner, all the belts on, drive train losses all add up. Then you will take the extra loss for elevation.

If this is a Cobra, the exhaust is fairly restrictive in most side pipes, unless you want to wear ear plugs. More likely to get 375 to the wheels at sea level on a 500 hp at the crank.

The old saying "there is no substitution for cubic inches" is correct when talking NA. Supercharging is like adding cubic inches. For every 15 psi of boost you are doubling the cubic inches. If you think of boost as adding cubic inches then "there is no substitution for cubic inches" is absolutely correct.

First can you drop a 351 Windsor block in your car? It can be stroked to 400 cid. If you go with a aftermarket block 4.125 bore you can easily stroke to 427 cid. You can get to 460 cid but there is no meat left on the bones for a rebuild.

If not, your 302 block can be stroked to 347 cid. If you go with an aftermarket block 4.125 bore you can get 364 cid. With some boost, say 5 psi those added cubic inches is 1/3 more than what you added. That 364 is like adding 82 ci if boost is 5 psi. So even if I was going to add a blower, I would at least stroke it out. The aftermarket block is much stronger and can take a lot more hp than the factory block, but you are talking $3000 in the block.

If you can drop in a Windsor block you can get there with a NA engine and still have a decent mannered engine. If you have to stay with the 5.0 block, I would go with boost. To keep it in your budget, stroke it for sure. I would go with aftermarket 4.125" bore block and keep the same heads, if I could afford it. Then blow air into it's nose. In your heat you are going to have to have an after cooler if you push much air. That is why you want as much cid as you can get to keep the needed boost down. With boost I wouldn't worry about the heads. You may want to drop the compression for boost. Keeping boost under 5 psi and dropping the compression to 8:1 you may not need an after cooler, which is about $1500 savings - last I priced one.

Someone suggested laughing gas. It's relatively cheap to install. It just costs every time you burn it up and have to buy another bottle. Put a 150 hp wet shot on it. You need a way to back timing out. It is the cheapest option. Then save money for the big engine, when this one grenades. You shoot enough into it and it will break, so start saving.

See what Blylins can do for you with that budget. He actually builds engines for a living. I just talk about it.