EngineQuest Vortec
Lightning Cylinder Heads
The EQ Lightning cylinder heads were a key component in making our engine modification package a success. Without a doubt, one of the worst features of the production 305 is the factory "smog" cylinder heads, which are choking even at a measly 305 ci of displacement. With decent heads, a small engine can breathe, and that allows it to take advantage of its rpm potential to make power. Without good heads, it isn't going to happen. These Vortec-style castings are just the ticket, with the right size valves, at 1.94/1.50, to fit and function in the smallish bores. Besides good flow, price is a key consideration when dealing with a 305. Enthusiasts do not typically regard these as their "ultimate" engine, so very few would spring for pricey race parts. However, if a substantial improvement can be had at a modest cost, why not go for it?
Shaver Specialty Service, a legendary name in the sprint-car engine world, is our local dealer for these EQ heads. Shaver receives the heads as bare machined castings, and prepped our set in record time to make this dyno test a reality. The heads were milled 0.030-inch for a little more compression with the small, dished-piston test engine. Shaver's completed the assembly by fitting their assembly package, including the valves, springs, retainers, seals and locks. The heads were also flow tested, showing very respectable numbers, particularly considering the valve sizes.
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| Lift | Intake | Exhaust |
| 0.1 | 60 | 54 |
| 0.2 | 117 | 102 |
| 0.3 | 173 | 134 |
| 0.4 | 216 | 152 |
| 0.5 | 225 | 162 |
| 0.6 | 232 | 169 |
| 0.7 | 237 | 172 |