Of all the big-block builds in this issue, this one will have the most limited appeal, and we know that. To summarize, this article shows the process Westside Performance went through to build a better-performing big-block Chevy that looks like a stock, 325hp 396. Most people building an engine from scratch or freshening up their old one would likely go for bigger displacement, aluminum heads, and so on. But some people want their engine to look as stock as possible, including cast-iron heads and intake, but built to its fullest potential. We can totally respect that, too. Though that particular build won’t post the big numbers of an engine built with aftermarket parts, some creative thinking will get better performance than the stock engine could have hoped for.

Whether you want to build a stock-looking 396 is irrelevant. The most important concept to draw from this article is how to gain the most performance from the parts you have. Working within limitations that seem to restrict performance bore size and combustion chamber shape, for example, forces an engine builder to come up with creative ways to work around these confines to build an engine that’s better than the sum of its parts. With that in mind, let’s take a look at how Ted Toki, owner of Westside Performance, put together a 461ci big-block Chevy that still looks like a bone-stock 396.

The Starting Point
This engine was most likely an L-36 396 out of a fullsize Chevy circa ’65 or ’66. The bore and stroke were originally 4.094 x 3.76. It had 10.5:1 compression with oval-port, closed-chamber cylinder heads and a Quadrajet carburetor on top of a cast-iron intake manifold. These were rated at 325 net horsepower from the factory. Not bad, but it could be better.

For comparison’s sake, here are some other factoids:

396
402
427
454
BORE
4.094
4.126
4.250
4.250
STROKE
3.760
3.760
3.760
4.000

A popular big-block build is a 496-that’s a 0.060-over 454 (4.310 bore) with a 4.250 crank. Most big-blocks have a 9.800-inch deck height. Heavy-duty truck applications generally have a 10.200-inch deck height.

396, The Bad News
As we walked into his assembly room, Toki told us that of all the big-blocks, a 396 is the least desirable-almost as if he were bracing us for bad news. “With the small bore size, there aren’t a lot of pistons available. Same thing goes for the rings. Plus, the heads are terrible.” It turns out they are. Let’s investigate.

The Toki Solution

We’re just guessing here, but it would seem that Chevrolet had bigger bore diameters in mind when it designed the Gen II big-blocks. With a bore spacing of 4.84 inches and a potential maximum safe bore size of 4.625 inches (theoretically, for the big-block design-most 396 blocks can only be bored out to 4.250 inches), the 396’s 4.094-inch bore diameter is laughably small. Notice how the deck of this 454 block had to be notched to clear the intake valve? That notch is even bigger on a 396. This is why larger intake valves don’t work in a 396. Just like in the cylinder heads, air does not flow well within the confines of this bore size. Finally, the piston size is just strange. In the ’60s, pistons for 396/402s were more readily available, but with the trend toward building bigger-displacement engines, your options for pistons are limited.

You’d need a micrometer to discover that the valves aren’t stock. The intake valve is the same diameter as stock-2.19 inches, but the exhaust is 1.81 inches, up from the stock spec of 1.725. Toki says a bigger intake valve wouldn’t help-it would be shrouded even more in the combustion chamber. In a cool piece of trickery, he did use Manley stainless steel valves with thinner stems. Stock 396s are machined for 3/8-inch valve stems (as are most big-block Chevys). These valve stems measure 11/32 inch. “I really don’t know that it will make a difference at all, but they intrude into the port less. It couldn’t hurt,” Toki says. In addition to fitting the guides to the thinner-stem valves and adding hardened exhaust seats, Toki cut the spring pockets for bigger-diameter valvesprings and machined the guides to fit positive-style valve seals. Except for some minor hand blending to the exhaust port, no porting was done to the heads.

Toki told us how difficult it was to find long-slot stamped rockers-roller rockers are so popular…PARTS LIST
DESCRIPTION
PN
SOURCE
PRICE
Assembly lube
ACXAC-9900

$8.99
Piston rings
1/16

138.00
Cam bearings
FH615F
Competition Products
29.99
Core plugs
P102
Competition Products
7.99
Distributor driveshaft
8151
Competition Products
11.99
Fuel pump drive
CCA4616
Competition Products
13.99
Funky parts kit
FKC-3
Competition Products
7.95
Gasket set
RB-31170
Competition Products
39.99
Long steel rockers
N/A
Competition Products
80.00
Oil pump
N77
Competition Products
36.99
Hydraulic roller
396275/284
Isky
335.95
Hydraulic lifters
3970HYRT
Isky
645.95
Timing chain set
73142
Manley
94.50
Distributor
D100700
PerTronix
275.09
Wires
808290
PerTronix
60.87
Bearings
829KDSS
Pro Comp
69.95
4.155 piston
N/A
Ross
917.00
4.250-inch crankshaft
QT425
RPM
260.00
I-beam rod
CBC6385-I
RPM
525.00
Champion spark plugs
NY8
Westside Performance
31.60
Intake valves
11872-8
Manley
150.48
Exhaust valves
11381-8
Manley
150.40
7-degree valve locks
13084-16
Manley
51.20
Springs
22408-16
Manley
161.60
Retainers
23645-16
Manley
52.00
Spring cups
42126-16
Manley
67.20

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