Which Small Block is better, Chevy or Ford?

We all know Chevy was first to the mini motor V8 game with their 265 debuting in 1955 but who did it better, Chevy or Ford?

There's going to be a lot of hair splitting here and frankly, there should be. Both companies designed phenomenal engines and deserve a ton of credit for these machines lasting decades under the hood in various forms.

Scour the internet to find a clear definition of the difference between a small and big block and you're sure to find a bunch of subjective terms like bigger, more metal, larger cylinders, longer stroke, and so on with no clear point of demarcation.

In an effort to bring perhaps a little more clarity it should be mentioned that most V8's that are considered a "small block" have a deck height under 9.7" while "big blocks" tend to be above that. There's probably some of each that fall on either side of that point but that seems to be the most common denominator.

Since Chevy was "first" we'll start with them. The design slapped together by Ed Cole was no doubt revolutionary but the idea that led to it was quite simple. He went around to all of the different GM divisions, found out what they did best with their engines and put all those things together into a new design. For example, the stamped steel rocker arms were actually taken from Pontiac.

It was a tremendous idea that drastically cut down on the cost to manufacture each piece and afterward found its way under the hood of every one of the big 3 manufacturers.

Another nifty little part was hydraulic lifters first implemented by Cadillac on their V16 in 1930 but not widely used until the 1950's. The lifters were more expensive but costs were cut because there's no need for a complex rocker rail arrangement and labor is cut because it's much quicker to adjust a hydraulic lifter than to lash a mechanical one. Perhaps the GM executives were still weary from the failed experiment with Chevrolet's first V8 in 1917 that they said, "you can design a V8 as long as it's no more expensive than a straight 6 to make"?

Prior to hydraulic lifters a costly shaft mount rocker assembly was required

Being first isn't easy though and there were a few things that Ford did better, beginning with the 221 in 1961, then a 260 and 289 by 1963. The first and most obvious improvement - distributor position. Ford put their distributor right up front and center where it's easy to access, Chevy's sits way at the back of course.

Connected to the distributor is a shaft that drives the oil pump on both engines but Chevy's got Ford beat here. Chevrolet used a solid 1/2 steel shaft to drive the pump and it gives decades upon decades of reliable service. Ford on the other hand used a small hex shaft and it's not too uncommon for these shafts to snap in half leaving you with zero oil pressure. The aftermarket has come through with beefed up versions for this reason that are a worthwhile investment.

Chevy Oil Pump rod Ford oil pump rod with a twisted example

Just forward of the distributor on a Ford sits a thrust plate bolted to the block to help retain the cam. Is it really a problem that Chevy didn't include one on their small block until 1986? Not really unless you plan to install roller lifters but it's worth a mention. Ford's got a slight upper hand there.

Ford Small Block with thrust plate installed

Moving over and aft we find ourselves at the valve covers which are secured with only 4 bolts on a Chevy while Ford opted for 6. Anyone that's ever fought with trying to seal up the valve covers on their 350 knows this a bigger deal than it seems and again isn't something they solved until 1986 with center bolt covers. Just below that we come to the biggest performance difference, valve angle. The engineers at Chevrolet settled on a 23 degree valve angle which has a real bad tendency to shroud the valves against the cylinder wall. Essentially it acts like a reduction in the port size, adding a restriction which as we know smaller ports help to give better throttle response and low end grunt while a bigger port lends itself to producing more top end power. Same principles apply when it comes to valve shrouding.

Ford on the other hand opted for a 20 degree valve angle. This is probably the biggest contributing factor to stories of the 289 producing well over 400hp at a hair raising 8000rpm. While this could certainly be done with a 283, the 23 degree valve angle makes it a little more difficult. To put this into perspective a stock LS1 has a valve angle of 15 degrees. Another noteworthy design aspect of the Ford heads is that both the intake and exhaust ports are equally spaced. This is another feature the Ford shares with the modern day LS. There are a few benefits to this and without getting too deep into the specifics of it the benefit is ultimately improved flow. Hence the reason Pontiac redesigned the Big Block Chevy heads like this for Pontiac racing applications. Other benefits are that it cuts down on hot spots in the head on the exhaust side as well as allows for a bolt on both sides of every exhaust port. It's very common on the SBC for the header flange to warp and cause an exhaust leak between the two inner ports.

Chevy Exhaust Ports Ford Exhaust Ports

Now down to the deck height. The Chevy small block uses a deck height of 9.025" from the 265 all the way up to the 400. Ford used a deck height of 8.2" on 302 and smaller displacement blocks and stepped up to 9.5" on the 351 blocks. For the 302 with a connecting rod length of 5.1" and a stroke of 3" that gives us a ratio of 1.7. That's not a bad number to make a decent high winding screamer. On the 351 with a rod length of 5.596" and a stroke of 3.5 that makes a rod ratio of 1.59 which is still pretty good. On the Chevy side of things all the small blocks except for the 400 got a 5.7" rod. The ratio for a Chevy 283/302 is 1.9, 1.75 for a 327 and 1.63 for a 350. There's other things we could get into like journal sizes but we've been splitting hairs like lumberjack turned barber at this point and that stuff is going to play an even smaller roll than what we've gone over so far.

Going through the list Chevy's got Ford beat on oil pump drive and interchangeability. The taller deck height clearly gives Chevy the upper hand on rod ratio and interchangeability of connecting rods. Notice how we used the term "interchangeability" twice in the last 2 sentences? Because that's really Chevy's defining characteristic and it really is that good, but you already knew that. The decreased side load from the higher rod ratio should result in less wear to the pistons and cylinder walls over the long haul.

Ford takes the cake on head design. Simply put, it's just better. From the 6 bolts on the valve covers and equally spaced ports to the valve angle it actually shares more in common with an LS engine than it does the original Chevy small block. In many ways the Ford just seems overall more refined with things like a thrust plate for the cam and the distributor in the front is definitely deserving of at least an honorary mention.

The Chevy should also get an honorary mention itself for being the first to really show that you can produce a V8 engine cheap enough for everyone to afford and be placed under the hood of almost any vehicle.

But how do we really pick a winner? Ford gives us better high winding flow with a better valve angle but then goes the opposite direction with a lower rod ratio. It's worth mentioning however that while the rod ratio for the ford is slightly less than the Chevy for similar displacements it's actually still pretty good. The high revving 396 by comparison has a ratio of 1.63 so as far as the Ford small block goes its really not a factor. Considering overall design and all the factors put together as a whole we really have to give the design trophy to the Ford. As much as it pains a Chevy guy to say it. The added selection of Two different deck heights means you can opt for the smaller unit, a whole 3/4" shorter than the Chevy, for really tight spaces as well or go with a 351 block if you don't need the extra room. If this seems like a puff piece for the Ford I assure you it's not. The writer owns 4 Chevys and only 2 Fords.

As a blatant cop out we'll hand Chevy a participation trophy for interchangeability, simplicity, cost, and first out of the gate. But which one is your favorite and why?