This 350 crate short-block...
This 350 crate short-block could be the best option for the cash. At $1,150 shipped from Jim Pace, you could freshen up your heads, put in a decent cam and oil pump, and be off to the races with a new motor for about $2,000 total! This would be an awesome quick strike to replace a tired 305, and you could come back with better heads later. The components are good, and it's built by GM. All 5.0 or 5.7 components on your car will bolt up. GM Performance Parts has an interesting Web site feature (www.gmgoodwrench.com), allowing a prospective buyer to swap different parts onto a 350 crate short-block. GMPP then provides dyno charts for that combination.
A Turnkey Candidate
A quick search on the Internet gave us a new candidate: the Golen Engine Service 383ci/405hp TPI long-block (www.golenengineservice.com). This package is designed to replace a 305 or 350 engine under the TPI induction system and carries a price of $5,199 for the long-block (not including intake, water pump, distributor, and so on). Rated at a healthy 405 hp and 495 lb-ft of torque, it's almost double the power of the stock 350.
The component choices in this crate engine are aimed at an efficient and powerful daily driver or street car, and the use of HD performance cast pistons and crank is a logical choice to make if the engine won't be raced regularly or fed significant doses of nitrous.
Golen definitely went top-drawer with its choice of Air Flow Research 195-L98 pattern heads and the Comp Cams 112-degree-lobe-separation cam (the stock one is 117), spending money where it will be of most benefit to power production. The dyno chart on the site has the engine running with a smog-legal TPIS base and runners and a 52mm throttle body, so don't expect these figures with your stone-stock intake. Golen Engine Service recommends PCM's for less to supply a tuned chip for your individual combo, and if all external smog components are present and functional, it should pass smog.
Shipping an entire engine from Hudson, New Hampshire, ranges from about $250 to New Jersey up to about $450 to California. Although we are going to see what we can come up with on our own, the Golen engine would be a great value to readers in similar situations.
Budget Bullet Building Block
On the tight budget side of things, to restore the engine to health with minimum fuss and expense, we vote for the GM Performance Parts 12556121 350 Partial Engine. This short-block is brand new and features hypereutectic pistons, powdered metal rods, and a nodular-cast crank in a four-bolt main block with all bearings and brass freeze plugs installed. It lists for $1,153.95 from Jim Pace Pontiac, and that price includes shipping!
To bring our 350 back to health (or upgrade a 305-powered car), we could have purchased a new oil pump, gasket set, and a performance camshaft and timing set. The stock heads could have either been rebuilt or replaced with iron Vortecs (with caveats, see Heads of State below). With 64cc chamber heads, this engine will yield a compression ratio of 9.1:1.
These studs are painted red...
These studs are painted red to illustrate the 72-degree angle of the center (heat crossover) intake-bolt holes in the heads and corresponding intake-manifold bolt holes on many of the '87-'92 TPI engines. The port bolts (foreground) are at the normal 90-degree angle to the mating surface, but for reasons known only to GM, the center two bolts in each head were drilled at 72 degrees on these engines, preventing the interchange of these heads and intakes with the earlier 90-degree small-block Chevy pattern.
If your intention is to just build a stout 350 for daily use, this would be an excellent core to build on as all ancillary items down to the hydraulic roller lifters and spider from your engine can be reused in this block.
As value for dollar goes, this one is a hands-down winner. You can see more and order direct from the Jim Pace Web site, www.paceperformance.com. Though this choice is tempting, we will still build our own.
Heads Of State And An Intake
Our choice of cylinder heads will be critical to the power output. We evaluated a number of heads, and the consequences of ditching the stock L-98 heads requires a change of lower intake as well, adding another $400 to the equation. (This cost is not included in the Golen engine. It uses heads compatible with the restrictive stock intake.)
On a cost/value scale, we've heard many times that the Air Flow Research heads are not in the bargain-basement range but are among the best for making power. AFR makes both the SBC- and Vortec-pattern heads, and both list at the same price ($1,399 a pair) for 180cc intake-runner volumes. Although we feel confident these 180cc intake heads would produce good power numbers for our planned 383, we would probably opt for the larger-volume 195cc AFRs for the same price, although they are only available in the older SBC intake-port design.
One of the early, popular front-runner candidates for the office of cylinder heads is the venerable iron Vortec (truck) heads by GM. These heads are very well respected for their performance potential. Very good low-lift flow and highly efficient combustion chambers offer excellent power potential. However, as built by GM, these heads were intended for pickups and SUVs, so they aren't designed for higher-lift cams (the spring pockets must be machined for any cam that will give more than about 0.460 valve lift). Add to this that they come with press-in studs and will need guideplates, and the price of disassembly, machine work, and the hardware goodies moves what would have been the most cost-effective heads into the $1,000 range. In addition, they require a Vortec-pattern manifold. Although still several hundred dollars cheaper than any of the aluminum heads, they just don't seem as good a deal when we factor the results of the upgrades into the price.
The greasy small-block Chevy-pattern...
The greasy small-block Chevy-pattern intake (top) is inverted against the Vortec-pattern lower intake, available from Edelbrock and Scoggin-Dickey. This illustrates the different bolt patterns and lack of heat crossover on the Vortec heads. The ports themselves are taller and become narrower towards the floor on the Vortec heads, a trend that became much more dramatic in the LS-series engines that followed.
We also looked into the Avenger and Edelbrock E-Tec heads. The Avengers are fully CNC-ported, aluminum heads, similar to the AFRs, at $1,299 a pair, and advertise similar airflow numbers. We only know of two engines built with these heads, and they have reported surprisingly strong power figures. They look good and seem to perform well, but there is the "unknown" factor working against them, and they don't include guideplates, which we need for our Harland Sharp roller rockers. If you root for the underdog-especially one that has been extensively modified and developed-check out the Chevy Avenger heads at www.avengerheads.com
Since we have accepted the fact that we will need to replace our intake base no matter what heads we use, why not go with the newer Vortec pattern but in a modern aluminum head designed for performance valve-lift numbers? This led us to the Edelbrock E-Tec series heads, which are not CNC-machined but otherwise carry the modern centrally placed spark plug, big valves, screw-in studs, and guideplates, all installed and ready to go. Edelbrock offers the E-Tec series in both a 170cc intake-runner design and a 200cc version. Since we are looking at upgrading to the 383-cid version of our small-block, we decided to opt for the 200s and the matching Edelbrock Vortec TPI intake.