Emissions Legal 347 Short-Block

Admittedly, many 5.0 Mustang & Super Fords readers rate emissions compliance up there with flossing every night. It's the right thing to do, but no one really seems to care if you don't.

We can assure you that while our California readers don't floss any more than anyone else, they do stick much closer to emissions compliance. While we'd like to think the oppressive brown pall hanging over the Los Angeles basin has jump-started Californios civic sense, in reality it's the specter of governmental coercion that has turned opinion from evasion to compliance with the smog laws. Having to chassis dyno your Mustang for the state with a sniffer up its tailpipe every other year is a great motivator, after all.

Frankly, most longtime residents of the Golden State are, in the final reckoning, happy enough to have emissions testing. It's a pain, it's expensive, it's a definite crimp on automotive enthusiasm, but being able to breathe and seeing trees with leaves on them is nice too.

And it can also be good for business. Mark O'Neil, the big piston at Coast High Performance, has long offered a CARB-exempted 347 Street Fighter 347-E short-block for those wanting to do things the right way. Unremarkable from other 347s in most respects, the 347-E's big emissions' stick is its camshaft--it's key to making the -E engine both powerful and emissions legal.

Horse Sense: Combine California's strict emissions testing on newer carsand its benign, nearly rust-free climate, and you end up with a healthypopulation of nearly 40-year-old hot rods. In the Golden State,deep-breathing '60s Mustangs are not uncommon, and old Foxes never die.

As with all EFI camshafts, the Pro Mustang 4018 hydraulic roller Coast uses employs a 112-lobe separation angle to ensure adequate manifold vacuum. That's also a sign that driveability ought to be reasonable, and it is. The valve lift is 0.510/0.534 inch, while duration is a reasonable 222/232 degrees at 0.050 inch valve lift. Such specifications may not raise a drag racer's pulse, but they are definitely healthy for something you want to drive onto the emission inspector's dyno. We've made 425 hp with less cam and Z304 cylinder heads on our 347 Street Fighter dyno mule, so this bumpstick is clearly way out in front of an E303. And if you want just the cam, Pro Mustang has it for $189.99.

The pistons are also important to the 347-E meeting its emission goals. Coast uses its in-house Probe pistons--naturally--this time with a slight dish for compression compliance and a smooth flame front.