ZZ383 Short Block Upgrade - Stroker Ace

457 Horsepower From a Wallet-friendly 383

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Long before LS engines invaded our hobby like ants at a picnic, there was a day when the 383 small-block was one of the dominant life-forms of the hot rodding world. After all, affordable Gen-I 350ci engines were plentiful, and adding 33 extra cubes made a great engine even better.

GM had access to this kernel of knowledge just like everyone else and released a sweet little crate engine dubbed the ZZ383. It pumped out 425 horsepower, and back before we all became jaded in terms of power output, that was a damn respectable number.

We were looking for an engine to swap into a first-gen Camaro and came across a super clean ZZ383 short block. Someone had snatched some of the parts off it, (one of those other magazine guys, no doubt), and we decided to get it running to see if we could eke out a bit more power while staying tame for the street. We also wanted to keep the compression near the 9.6:1 that the ZZ383 crate engine shipped with.

 Zz383 Short Block Upgrade Short Block 2/22

Additionally, this gave us an excuse to fondle the new 23-degree intake manifold and head combination from Racing Head Service (RHS). We recently checked them out at the SEMA show and thought the idea of having parts that fit small-blocks, both new and old, was pretty cool.

With parts in hand we headed over to Don Lee Auto in Rancho Cucamonga, California, to breathe new life into our ZZ383 short block.

01. Our starting point is this clean ZZ383 GM Performance Parts 383-inch short block. It came with a forged 3.80-inch stroke crank, heavy-duty steel rods, and hypereutectic aluminum pistons. Fitted with their fast-burn heads, this GM crate engine was rated at 425 hp and 449 lb-ft of torque. Good numbers, but we should be able to do a touch better.

 Zz383 Short Block Upgrade Starting 3/22

02. We ditched the conservative factory 222/230, 112 LSA camshaft for a COMP Xtreme stick (PN 08-467-8, $297). The new cam wasn't crazy big (230/236 duration, 112 LSA), so it should be easy to live with on the street. Once slid into place, we secured it with the cam plate and a set of ARP cam bolts (PN 134-1001, $4).

 Zz383 Short Block Upgrade Comp Xtreme 4/22

03. The ZZ383 short-block didn't have a timing chain, so we ordered up a nice double-roller timing chain and gear set from COMP (PN 3136, $72) and locked it down with some ARP fasteners.

 Zz383 Short Block Upgrade Comp Double Roller Timing 5/22

04. The GM fast-burn heads that came with the ZZ383 had 62cc chamber volume, which gave the long-block crate engine a 9.6:1 compression ratio. Now, given today's gas prices we don't mind a lower compression for a street engine, but we certainly didn't want it much lower. We settled on a pair of RHS Pro Action aluminum heads (PN 12056, $1,365 pair). The 220cc intake runners should supply plenty of air, and the 64cc chamber volume will only tick us down to 9.5:1 compression, so we can cruise on cheaper gas or eventually add a little boost.

 Zz383 Short Block Upgrade Rhs Pro Action Aluminum 6/22

05. The fully assembled RHS heads featured manganese intake and bronze exhaust valveguides, hardened valve seats, and came fully assembled with 2.02-inch intake and 1.60-inch exhaust valves. The heads also had pushrod guides and screw-in rocker studs. A nice design feature is that the heads accommodate both perimeter and center-bolt valve covers.

 Zz383 Short Block Upgrade Fully Assembeled Rhs 7/22

06. To secure them to the block, we used a set of Fel-Pro PermaTorque head gaskets (PN 7733PT2, $12 each) and a set of ARP stainless head bolts (PN 434-3601, $167). If you want to save a few bucks you can get the bolts in black oxide for $77 a set.

 Zz383 Short Block Upgrade Fel Pro Perma Torque Head 8/22

07. We didn't have a timing cover, and even if we had, the plastic GM piece from the crate engine isn't reusable. An easy and better-looking solution was this slick two-piece timing cover. For applications requiring a thrust button, the rigid design helps stop flex, which can cause erratic ignition timing. In our case, it looked killer and the two-piece design will make future cam swaps easier.

 Zz383 Short Block Upgrade Two Piece Timing 9/22

08. To pair up with our COMP roller cam, we tossed in a set of their High Energy roller lifters (PN 850-16, $217). These are a great and economical replacement for stock hydraulic roller lifters.

 Zz383 Short Block Upgrade Comp High Energy Roller 10/22

09. Luckily for us, we had the GM "spider" and lifter guides. Working with this later-model roller block just made the whole build easier.

 Zz383 Short Block Upgrade Gm Spider And Lifter 11/22

10. We then installed the Rattler Torsional Vibration Absorber from TCI. For our externally balanced engine, we chose part number 870003 ($402). The Rattler is designed to absorb rather than just dampen vibrations and is SFI 18.1 certified.

 Zz383 Short Block Upgrade Tci Rattler Torsional Vibration 12/22

11. Three of the bolts on the four-bolt-main block had extended shafts for holding the GM windage tray. Since we're ditching the stock pan in favor of one with better oil control, these ended up being problematic. Our two options were to replace them or cut off the three shafts. We chose the cheaper option.

 Zz383 Short Block Upgrade Four Bolt Main 13/22

12. We went with this Moroso high-volume oil pump (PN 22146, $122). A real time saver since the pickup came factory-welded to the pump to ensure 0.25-inch clearance to the bottom of the pan. The pump came with a new driveshaft and was secured with an ARP pump stud kit (PN 230-7003, $6).

 Zz383 Short Block Upgrade Moroso High Volume Oil 14/22

13. Controlling the oil not only helps your engine survive hard driving; it also helps it make more power. We snatched up a 7-quart Moroso pan (PN 20206, $256) and their reusable one-piece gasket (PN 93151, $19). The pan came zinc-coated with an integral windage tray and can accommodate strokes, with an OE-style rod, of up to 3.800-inch. The baffled pan also had a crank scraper. We bolted it down with fasteners from our stainless ARP master assembly kit (PN 534-9601, $133).

 Zz383 Short Block Upgrade 7 Quart Moroso 15/22

14. We decided to splurge on a set of COMP Ultra Gold rockers (PN 19004-16, $308). They are rock solid and will help keep our valvetrain stable in the upper rpm range. Also, the full-roller design will free up a bit of power.

 Zz383 Short Block Upgrade Comp Ultra Gold 16/22

15. For an intake, we wanted to try out RHS' new 23-degree manifold (PN 12902, $300). It's engineered to port-match-fit the RHS heads we're running, and the single-port high-rise design is set up to optimize mid-range torque. One really nice feature is that it fits all versions of small-block Chevy cylinder heads, including Vortec GM heads. The manifold also features auxiliary water ports, integral water crossover, and dual side distributor mounting points. For the more hard-core crowd, it also has water ports at all four corners for reverse cooling applications.

 Zz383 Short Block Upgrade Rhs 23 Degree Intake 17/22

16. To put fire in the hole, we installed a PerTronix Flame-Thrower plug-and-play billet distributor (PN D7100710, $257). This included their Ignitor III electronic ignition module and a CNC-machined 6061 T-6 housing. The adaptive dwell will maintain peak energy output through the entire pull and should help minimize misfires. It also has a rev limiter function and has both vacuum and mechanical advance.

 Zz383 Short Block Upgrade Pertronix Flame Thrower Billet 18/22

17. To top off our engine, we went with Holley's new Ultra Street Avenger carburetor (PN 0-86770HB, $567). The 770 cfm size is perfect for our stroker, and the electronic choke will make it easy to live with on the street. The carb features ultra-lightweight aluminum construction along with billet metering blocks and base for increased strength over cast pieces. Due to glass fuel level windows in the bowls, it's easy to adjust.

 Zz383 Short Block Upgrade Ultra Street Avenger 19/22

18. After topping off our heads with a set of black RHS valve covers (PN VC-12000, $166 including breathers), we strapped it down to the Superflow 902 dyno at Westech Performance in Mira Loma, California. The engine was filled with seven quarts of COMP's muscle car 10W30 ZDDP-enhanced mineral-based break-in oil and ran through a cycle on the dyno to help seat the rings.

 Zz383 Short Block Upgrade Black Rhs Valve 20/22

19. After a few pulls, we had the timing set at 37 degrees and then used the appropriate copper widgets to limit the mechanical advance to a maximum of 12 degrees. We also set the rev limiter to 6,400 rpm. The small springs are used to adjust the rate, or speed, of the mechanical advance. Our dyno operator, Steve Brule, swapped the secondary jets from 80 to 84. The rest was good to go right out of the box.

 Zz383 Short Block Upgrade Set Rev 21/22

20. We nailed down a best pull of 457 hp (at 5,900 rpm) and 451 lb-ft of torque (at 4,700 rpm). We were pleased with the flat torque curve, and the valvetrain was still stable at 6,000 rpm with zero signs of valve float. We could have made around 20 percent more power by bumping the compression up a full point, but this combo will run detonation free on our cruddy California swill. We'll also be able to cruise around town on the cheaper grade of gas, and that's cash in our pocket.

 Zz383 Short Block Upgrade Graph Sheet 22/22


Westech Performance
Mira Loma, CA 91752
Racing Head Service
Memphis, TN 38118
TCI Automotive
Ashland, MS




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