Technical Best Performing "Traditional" head for a 283 build

Hello,

In our teenage experience with motors, speed parts and cost effective purchases, the exotic cams from the popular manufacturers were very tempting. The performance numbers shown in the sponsored cars were always shown in the weekly ads in the Drag News publications. “Isky equipped sets this record, Engle Cams rolls over the competition, Howard Cams develops the 5 cycle cam for all motors and racing…etc.”

We had a friend that ran a 56 Chevy Bel Air hardtop in the stock classes until he got wind of more power in his SBC motor. So in the increments over the months, he went to a 283, then a 301 to boost his horsepower and winning stock body cruising and racing. But, at the time, no one was using a stock body Chevrolet sedan body and making big time runs that amazed everyone. Other than Tom McEwen and his continuous models of Chevy sedans in Bixby Knolls. No one ever found out what he ran or built into his motors. “It came that way from the factory…” Yeah, right… until it met Reath Automotive Speed Shop. Ha!
Lion's Dragstrip 1959
The aspect of building a fast Chevy sedan works in any era. This turquoise/white 56 Chevy was one of the fastest Chevy sedans in the Long Beach Bixby Knolls area. When Tom McEwen moved on to racing other hot rods and competitive race cars, this one was the faster Chevy sedans. We all know the ruling Chevy sedans in the late 50s was the series of 55, 56, 57 Chevy sedans from the McEwen camp. He wanted everyone to think those sedans were “stock!” Then, before he moved on to fame… he was in the Gas Coupe/Sedan Classes and we all knew why…
56 Chevy at Lion's Dragstrip

The 1956 Chevy Bel Air Hardtop he drove daily to school and work back then, sounded fast with a rumble. It was fast, according to my brother, and stories about the build flew like hotcakes in the teenage circles. A 265 with a 4 barrel and cam, to a 283 with dual quads, a 301 with a cam, head work and headers, to a possible ½ inch stroker motor from Reath Automotive that looked like all of the SBC motors he had in the engine compartment. For some reason, no one knew what was in the engine build, except for the original 265 with a 4 barrel.

It was on a lowered rake, looked mean and was fast with the vast array of unknown modifications after the 265 with a four barrel motor... yikes! The primary cam was a stock Duntov from the factory parts department.
1959
But, once he got to Lion’s Dragstrip to race, there were enough protests to make sure those Chevy sedans went into the Gas Coupe and Sedan classes. This was the era of fast sedans left in a stock height or lowered to showcase the power built into the motor/transmission.

But, somehow, it was a fast hardtop sedan. Faster than most cars around the Bixby Knolls cruising grounds, according to my brother. The motors had to have been larger than most on the street.

The guy with the 56 Chevy was one of the early guys who started modifying his car. He liked being the top dog at the teenager hangouts and gabfests. The facts were slowly coming to light.
reversed photo to show white shoe polish class identification... C/Gas or C/Stock?
The reversed photo shows the Lion’s Dragstrip classification. We knew back then, but for all of these year later, the classification is a mystery. A 265 would put the 1956 Chevy in C/Stock... whereas, the 301 or 352 SBC mods would have put him in C/Gas.

There were very few 301 SBC motors in a 1956 Chevy or for that matter, any Chevy sedan back then. The only other guy may have been Tom McEwen and his string of 55, 56, 57 Chevy sedans with modified motors… Of course, we all have seen the Lion's Dragstrip classification photos showing D/Gas or C/Gas... Same neighborhood, same high school, same Chevy sedan type, but different timeline listing.

But, the topper was and still is a mystery, the 56 Turquoise/white Chevy may have had a Stroker Kit from Reath Automotive to create a huge 352 C.I. SBC motor. No one alive ever had proof, although we did see the 56 Chevy Bel Air in action.

Jnaki

So, what were the heads he used? As a matter of fact, most local racers used Chevy truck heads to start the modifications, then off to “local” Bixby Knolls, Jocko’s Porting Service to clean and do his magic for more power. But, because the ported and polished heads could not be seen, it “could” have been done to gain a little more speed over the others. One pits area tear down protest would have taken care of that mystery. The motors in the 56 Chevy Bel Air Hardtop always looked like they came from the dealer’s showroom floor. Who knew?


When we started our 1940 Willys Coupe build for B/Gas competition, we had our Chevy truck heads ported and polished at Jocko’s. It was just one step in the right direction for us.

Then, as the competition was furious, we stepped into another arena with a larger motor, better parts and still used the Jocko’s ported Chevy truck heads. Now, sitting over all blower spec racing parts in the last build of our 292 SBC motor with a new 671 Supercharger.

A similar motor helped us get close to the national record for the C/Gas Coupes/Sedan Class. 6 Stromberg Carbs and all, before the rush of Hilborn Injectors became the go to set up… But, Hilborn Injectors for a street legal coupe? In daily traffic for cruising to high school? The trend and rules were just beginning its march for more competition and faster times, so the rules were relaxing. Although a Hilborn Injector set up for daily use? Ha… good luck… YRMV

 

Revisiting the 520 discussion...

Does anyone have photos of the early combustion chambers (stated 60-64) vs the later combustion chambers (stated 65-67)?

I have 1 set and want to know if I use those or one of the sets of 896 (one with triangle below cast number and one with "T" below).

 

Thanks @HEATHEN

Mine are the later year configuration (top photo) and confirmed by date code of "C 1 7" March 1967. I'' tag these for use and stick the others on the shelf for a budget build.

 

So when I get around to searching for heads for my 283 retro build, what casting or part numbers of heads will have the small chambers, best port size, AND the offset valve cover bolt pattern? I'm not building a race car engine. Just a fun "little" engine that uses mostly nostalgic parts.

 

So far as offset bolt holes go, they went until the spring of 1959. I had a set of heads with a March '59 casting date that were still offset, and a pair from May of '59 that were straight across. 1957-59 power pack heads all have the same style combustion chambers, and I don't believe there's a noticeable difference in port volume; '56 power pack and '57 270 hp heads have chambers that are a bit smaller. Casting numbers on the underside of the heads are 306 in '56 (this one does have smaller intake ports than the rest), 539 in '57, 770 in '58, and 550 in '59. The '57 270 hp heads have a different casting number of 997, but the chances of finding a pair of them are pretty slim. There was also a late '56 head for the 240 hp 265 dual quad engines with a casting number of 762, also quite rare. So far as looks go, the '58 and '59 heads are going to have a '69 and newer look on the end of one of the heads due to the fact that if the vehicle had the optional air suspension in those two years, the compressor bolted to the end of the head.

 

# 186..

 

Thanks. Yes, I see that on the heads on the 283. They are undrilled on the low compression heads on it, but the bosses are there.