What route for fueling would be the best route? EFI or Carb? What are the pros and cons of the two? I know EFI will be more expensive but easier to tune. I also know carbs have come a long way since so I’m sure they are easier to tweak although I don’t have experience with carbs. I’m sure it isn’t to much to learn and you don’t have to rely or be at the mercy of your tuner. Or have to pay what $450 a file.
Having a clear idea of how the car is going to be used will really help you figure out where to spend your money. The SBF from 289 all the way to 5.0 is basically the same block, and with the exception of the Boss 302, all the heads, intakes, and front timing covers swap easily.
The biggest bottleneck to making power on any 302 (or even 351) will be heads. They were designed for a little 221 cubic inch motor, and the ports are tiny and restrictive. The early higher-compression chamber heads were mediocre (though they can be greatly improved by expensive porting up to about 1970), and they only got worse over the years. Even the very best factory heads, the GT40 and GT40P, (which were improvements over the 70s and 80s smog heads) will struggle to make power over 5k in stock form. Your best bet is to go with the best heads you can afford, for starters, if you want to make good power. The chamber design on any modern aftermarket head really helps, because their heart shape improves burn speed, and allows much more complete consumption of fuel to make power. Better horsepower, better economy. Ignition timing doesn't have to be set so early, and that means your pistons aren't fighting an explosion on the way up, making your engine more efficient.
Once you pick out heads that match your wallet and power-making needs, take a look toward exhaust. The stock cast iron manifolds suck, and the shorty tubular headers that most 5.0 engines came with are not that great either. For a street driven car, the broad powerband boost you get from a good set of tri-y headers is a big help. For a drag car, long tube equal length headers get a big boost on the top end, and are the only way to go. Often, both tri-y and long tube headers will show an improvement throughout the powerband, thanks to the fact that they let the spent exhaust out faster. For most 302-347 engines, 1 5/8" primaries are the way to go. If you're honestly over 400 horsepower, you might step up to 1 3/4".
When it comes to intake, the stock Ford EFI setup really is pretty good at producing low end torque for a mild street engine. The later ones off a Mountaineer or Explorer are even better, similar to the rare GT40 intake. The GT40 style intake (round staggered lower ports instead of square ports down the middle) becomes important if you have anything besides factory heads. Even then, for serious performance, most people will get the lower intake ported.
If you are starting from scratch and have to get everything anyway, it's not a bad idea to skip all the stock Ford intake parts, and go right to a good carburetor style intake. For up to around 350 horsepower, with street use in mind, it's hard to beat the Weiand Stealth. It's an excellent dual plane with great torque production, and fits under most hoods easily. If you don't drive in cold weather, and have plenty of hood clearance, the Edelbrock RPM air gap is even better. If you only care about the top end charge, and want to make higher peak horsepower (at the sacrifice of low end throttle response and tire melting fun), you could go with a good single plane. The mildest of those would probably be the venerable Torker 289 (not Torker II which isn't so great), followed by the Vic Jr. and Parker Funnel Web. They will probably add 15-30 horsepower on the big end, but as stated, will take it away down low at about the same proportion. You'd need a nice high stall converter to make any of those worthwhile, if you happen to have an automatic.
EFI or Carburetion? Well, that's always a tough call. In the 60s, if your engine had 100k miles, it was shot. Definitely due for a rebuild. These days, cars are expected to run for 250k miles without much beyond basic maintenance. The biggest reason for that? EFI. With fuel injection, you aren't washing your rings with fuel every time you let off on the gas. The improved mixture quality also helps prevent detonation, hot spots, and valve wear. But carbs are cheap! And some of 'em are pretty good.
Some of the best carbs not only make similar or better top end power compared to EFI, but they can also achieve fuel-injection quality mix. But to make that work on your engine, you are going to need to size accordingly. If you really only care about drag racing, for a 289-347 CID engine, the venerable Holley double-pumper 650 might be a good choice. Tuned properly, it'll probably make better power at WOT than any EFI system you can find, too. As for driving around on the street though, it's going to stink. Literally. Because while big fat drops of fuel don't take up much room in the intake and allow a lot of air to get in the cylinders, they also don't burn well. Your engine will be spitting a lot of unburnt hydrocarbons out the exhaust, and it'll have terrible manners at low RPM and part throttle.
Realistically, a 289/302 is never going to need more than about 500 CFM, even at 5500 rpms. However, if you're getting really good volumetric efficiency, and want to make sure there's no restriction, a good 600CFM carb with
ANNULAR BOOSTERS and vacuum secondaries is an excellent choice. Those produce excellent fuel delivery even at low flow, creating a fine mist instead of raining fuel into the intake. For all out drag racing, they may cost you a few horsepower on the big end, because the atomization becomes so fine, they are delivering mostly fuel vapor instead of droplets, and compared to the down-leg boosters of a Holley, could hurt you by 5-15 horsepower. When driving around on the street though, unlike a double-pumper, they are always smooth, crisp, and eager to make tire smoke at any speed or throttle position. The massively improved fuel economy and lack of fouled spark plugs is a nice bonus. For this kind of carb, take a look at the venerable Autolite 4100, or its much easier to find and tune descendant, the Summit M-series carburetor. Edelbrock's AVS/2 isn't bad either. Annular boosters are the way to go for any street driven carb.
If you can afford to, or if you just don't want to rebuild your engine after 100k miles, take a look at some of the newer carb-style EFI systems. The Holley Sniper is freaking fantastic, and it looks like the new Atomic EFI II system is going to be a real winner too. The port injection systems available from Edelbrock (and some others) is also worth mentioning. Frequently, in our engines, the throttle body 'carburetor style' systems (wet manifold) can offer slightly more power, because the cooling effect of the fuel coming into a hot intake will create a denser intake charge. How much difference it would make compared to a port injection system that runs only air through the manifold, and squirts the fuel directly at the back of the valves is anyone's guess. I personally feel like either setup is going to be superior to most carbureted setups in every way except price.
The last option is one that doesn't even get mentioned very often, due to price and complexity.
8 stack injection.
It'll set you back easily as much as you spent on the rest of the engine, typically, and figuring out how to set up air filtering and cold air intake for it is a pain in the butt. But 8 velocity stacks, with 8 injectors, feeding 8 intake valves is the best way to make big power throughout the broadest range of RPM. With any plenum type intake, each pulse from an opening valve is sucking air and fuel from the manifold. At certain RPMs, those pulses can 'steal' a bit from other intake runners, or worse, with a cam that has a lot of overlap, exhaust can backflow into the intake, contaminating the charge and even being sucked into other cylinders. With an individual-runner manifold, each cylinder has a nice orderly stack of pulses in a pipe above the valve. They don't share with each other, and each cylinder has a tremendous amount of air and fuel available at any given time.
Is it any good?
Well, I've seen an engine that produced peak torque at 2500 RPMs with a redline at 7k, using this. It was making about 550 horsepower on the big end, if I recall correctly, with over 450 lb-ft of torque on tap through most of its range. If that kind of a flat power band doesn't impress, you'd better check your pulse. Keep in mind, this was with a small block Ford!
Will you be able to achieve those numbers if you get one too? Probably not. Unless you have a bank account bigger than a politician's ego, you'll be hard pressed to make all this stuff work to its full potential, on a budget. Still, the people selling these (like Jim Inglese) are very supportive and they have a phenomenal product.
Stick with hydraulic roller cams, if you have a choice. Solids require significant attention and frequent maintenance, if you're doing it right. Go with a cam that will match the way you intend to actually use the car, in the RPM range you want. When it comes to lift, keep your valve springs in mind, as well as piston clearance. When in doubt, pick the milder cam, not the wilder one.
If you need to rebuild your engine's bottom end, you might consider going with a stroker kit. It probably won't cost more than getting the factory crank balanced and reground anyway. The 331 is probably better for longevity and peak horsepower, while the 347 produces more friction and side-loading, but also a lot more torque from very low RPMs. There's no wrong choice there, with modern stroker kits from Eagle and Scat.
Lastly: Turbos and supercharging, along with nitrous: If you go this route, unless you're putting boost on something with stock heads, you'd best buy an aftermarket block that can handle it! Richard Holdner has been able to make hundreds of dyno runs on stock block junkyard engines producing sometimes north of 700 horsepower. However, that's in a dyno room. In the real world, most drag racers will tell you that the limit of SBF's is somewhere north of 400 horsepower, and that 500 is just a ticking timebomb of split-block goodness. If you build an engine that runs great N/A, then putting on a power adder will just make it run better. Simple. Heads are NOT as critical for boosted applications, and offer less return for the money, since you're just shoving air and fuel in, and the turbulence of a restrictive port doesn't seem to hurt too much.
If your eyes aren't too glazed over, and you're still conscious after reading this giant post, I hope you got some good info out of it, and that it helps you with some of your choices.
Best wishes!
