Homebuilt Old-School Small-Block

Part 2: Top-End Revival

By Jason Lubken – Photography by the Author

If you have been following along, in last month’s issue we gave you the rundown on how we assembled the bottom end in our little homebuilt small-block Chevy. Now comes the fun part—heads, valvetrain, and the finishing touches. Working with a basically stock rotating assembly, it’s still very feasible to squeeze out some extra power. The next big priority was bolting on a great set of heads. It’s a practice hot rodders have played with for over a century, and the concept is simple: higher compression plus better airflow equals more power. But we also wanted to be careful not to sacrifice reliability and driveability.

Roller tip or full roller rocker arms small-block Chevy
Since these heads require larger-diameter valvesprings, they cannot be used with stock stamped steel rocker arms (pictured on right). Roller tip or full roller rocker arms must be used with large-diameter springs. We chose Comp Cams Ultra Pro Magnum Roller Rocker Arms for 7/16-inch studs at a 1.6 ratio to achieve max valve lift (PN 2821605). These are stout, featuring oversized trunions, needle bearings, and hardened roller tips.
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The horsepower per dollar scale is always tough when you’re on a budget. You want that best- bang-for-your-buck type of thing. Reliability and longevity are worth something, too. I was looking for the best of both worlds when it came to the engine—that perfect mix of driveability but with an old-school muscle vibe.

small-block Chevy Comp Cams’ Beehive 280-pound valvesprings

Along with roller rockers, we ordered a set of Comp Cams’ Beehive 280-pound valvesprings (PN 26986-16), Comp spring retainers (PN 787-16), locaters (PN 4696-16), locks (PN 648-16), and a set of Manley stainless 2.02/1.60-inch intake and exhaust valves (PNs 91014141-1 and 91014146-1). Always consult your cam card for the required set of valvesprings. Note: With new valves, we had a valve job done at our local machine shop prior to install, which is not necessary with assembled versions.When you dive into it, it’s not hard to find a great set aftermarket heads, or even factory options when budget is a high priority. A set of iron Vortecs (L31 ’96-’00 truck and SUV) could work for some applications, but with higher-lift cams they require additional machine work at additional expense. After some cost analysis and shopping around, I looked to Speedway Motors for help.

calipers
We’ll check two main measurements before we final-assemble the heads. First, with a set of calipers, we’ll verify that we have the proper valvespring installed height and shim when necessary.
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After working with one of their lead techs, they pointed out the new Speedway Motors aluminum double-hump heads, which really checked all the boxes. They’re sold assembled or bare at a budget-friendly price. Performance wise, expect a little bump in compression with 64cc combustion chambers, and with 2.02- and 1.60-inch valves, better-flowing intake and exhaust runners, they should outperform many of the other aftermarket options. Best of all they’re packaged with that old-school ’60s fuelie look.

Checkout this Bowtie Boneyard: Small-Block Smoggers

 installing the valves small-block Chevy
We started by installing the valves with a small amount of assembly lube avoiding any metal-on-metal contact.
verifying each spring install height with a set of calipers
With the valves installed, spring retainers, locaters, and locks in place, we held a straightedge on the bottom of the spring retainer and verified each spring installed height with a set of calipers. Reference your cam box for the recommended installed height and shim, if necessary.
small-block Chevy valveguides
With our spring height verified, we moved onto assembling the rest of the valvetrain components. These valveguides are machined with modern, positive stop stem seals with a 0.540-inch od. We also used a valve stem seal install tool to prevent damage to the seal. Be sure to use a dab of engine oil on each valve stem prior to installing the seal.
valve seal spring compressor tool
After the valve seals were in place, we clamped down our springs using a trusty spring compressor tool. It can be helpful to have an extra set of hands here.
ARP high-performance 7/16-inch rocker arm studs
Next, we installed a set up ARP high-performance 7/16-inch rocker arm studs (ARP PN 100-7101) and Dart (PN DRT-27001110) pushrod guideplates for 5/16-inch pushrods. Note: These heads are designed to only be used with pushrod guides.
small-block Chevy installing the heads
After the springs were installed, we moved onto installing the heads. We used a set of Fel-Pro’s thin 0.015-inch shim gaskets (PN 1094) for a little extra compression. We applied a coat of copper gasket spray to each head gasket before installing.
ARP head bolts thread sealer
We used a new set of ARP head bolts and applied some thread sealer before torquing the heads. Speedway recommends torquing the heads to 50-65-80 lb-ft.
Comp Cams Short Travel Retro-Fit hydraulic roller lifters
We installed a set of Comp Cams Short Travel Retro-Fit hydraulic roller lifters (PN 15853-16). Before install, we let them soak in a can of engine oil to be well lubricated.
Manley’s pushrod length tool (PN 42132) and adjustable-length tool set (PN 7705)
Checking for the pushrod length we used Manley’s pushrod length tool (PN 42132) and adjustable-length tool set (PN 7705) to verify the length of our pushrod. Make sure your lifter is setting on the base circle of the cam lobe (valve closed) before checking this measurement. We came up with Comp’s 7.300 and ordered a set of Magnum pushrods for guideplates (PN 7609-16).
Appling assembly lube to every contact surface
After the pushrods are installed and before installing the rockers, we applied a dab of assembly lube to every contact surface.
small-block Chevy lifters and pushrods
Here’s a look at our lifters and pushrods prior to installing the rocker arms. We rotated the crank to TDC #1 to begin our tightening procedure on the rocker arms.
Comp roller rockers
Note the trunnion seat on these Comp roller rockers—the poly locks can only seat against the flat side of the trunnion—be sure this side faces up when installing the rockers.
preloading each of the lifters and lock down the poly lock
With the spark plugs removed and engine at TDC #1 cylinder, we set all the loose rockers to zero lash (slight resistance spinning the pushrod in your finger), then turned the engine over 180 degrees at the crank and repeated the step. Last, we added a half turn of preload to each of the lifters and locked down the poly locks.
high rise/dual plane Weiand Speed Warrior intake
We picked out a high rise/dual plane Weiand Speed Warrior intake (PN 8501WND) promoting a broad rpm powerband. The best matched set of intake gaskets are Fel-Pro’s (PN 1205) that also have rubberized coolant port seals.
high-temp sealer around water jacket port
Before installing the intake, instead of using coolant jacket gasket seals, we typically use a high-temp sealer around the outside water jacket ports on the top and bottom of the intake gasket. This also helps hold your intake gasket in place prior to installation.
sealer to the front and rear valley rails
We also applied about a ¼-inch bead of sealer to the front and rear valley rails—this technique has been proven time and again over a factory-type rubber seal.
installing intake small-block Chevy
After installing the intake, we final-torqued it to 25 lb-ft, starting at the inside moving outward and let the sealer cure before moving onto paint.
small-block Chevy prepped for paint
We ran the engine over to our local paint shop and prepped it for paint. A factory timing cover and oil pan was installed before we taped off necessary ports and prepped the surfaces for paint by scrubbing with wax and grease remover several rounds.
three-part epoxy primer/sealer
A three-part epoxy primer/sealer was applied …
small-block Chevy single-stage Chevy Orange
… before laying on three heavy coats of single-stage Chevy Orange.
’63 Chevy Impala Engine Bay
Here is the engine dropped in our ’63 Chevy Impala and dressed in a set of Speedway Motors tall finned aluminum valve covers, Corvette-style 2½-inch Ram Horn–style exhaust manifolds—topped with a Holley 750-cfm double-pumper carb and a Speedway Motors 12-inch dual finned air cleaner to tie it all together.

Interested in Seeing More: Al Noe’s ’67 Camaro RS/SS

TECH CHECK
Engine
Displacement: 355 ci
Compression Ratio: 10.1:1
Bore: 4.250 inches
Stroke: 3.480 inches
Cylinder Heads: Speedway Aluminum Double Hump
Rotating Assembly: Stock crank and rods, Sealed Power flat-top pistons
Valvetrain: Comp Cams Aluminum 1.6:1 roller rocker arms, 3/8-inch pushrods, roller lifters
Camshaft: Comp Cams (0.527/0.544-inch lift; 224/234 deg. duration at 0.050)
Induction: Holley 750-cfm Double Pumper, Weiand Street Warrior intake
Ignition: MSD Pro Billet Digital E-curve, MSD 8.5mm wire, NGK plugs
Exhaust: Speedway 2½-inch ramhorn
Ancillaries: Factory
Output (at crank): Estimated 405 hp and 385 lb-ft

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Sources
No Coast Custom & Rod Shop
(402) 325-4686
nocoastcustomandrodshop.com

Speedway Motors
(855) 313-9173
speedwaymotors.com

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