Compression Ratio Is the Decision

Everything else follows from one number, and getting it wrong is the most expensive mistake in an engine build.

  • 8.3:1 forged (+.020") — for boost. Low compression gives the detonation margin that lets a turbo or high-boost supercharger make real power safely.
  • 10.0:1 forged (+.040") — the sensible performance compression for a strong naturally aspirated engine or a mild low-boost build.
  • 12.5:1 forged — race compression. Race fuel and naturally aspirated only.

Fitting high compression pistons and then adding boost is how engines get destroyed. Decide which one you are building before you order.

Street pistons

For a rebuild rather than a race build, the Street Performer sets come complete with rings: STD, +.020", +.030" and +.040". Matching Hastings ring sets are available separately.

All of our forged pistons ship with gas nitride rings as standard — originally developed for boost, and useful on any engine because the material seals at a thinner cross-section, reducing friction.

Connecting Rods

Crossbeam rods are custom made and suit anything from stock-style to high-torque long-rod engines — fully balanced with bronze pin bushings and ARP rod bolts. The best chromoly rod we offer.

Chromoly H-beam rods are the more affordable route to a rod that will take serious power.

The honest guidance: a healthy factory rod is good to a surprisingly high power level. Upgrade when you are adding serious boost or serious rpm, not as a default.

Bearings

  • Standard main, rod and thrust sets for a normal rebuild, plus 0.25mm and 0.50mm undersizes for a ground crank.
  • Coated sets — the coating survives moments when oil film is marginal, which is exactly when a bearing gets hurt. Worth it on any engine seeing boost, high rpm or steep angles.
  • Clevite 77 and Safety Auto rod bearing sets for different budgets.

Measure your crank before ordering. Undersize bearings on a standard crank, or standard bearings on a ground one, will destroy the engine on the first start.

Studs and Fasteners

The Pro main stud set clamps the main caps more evenly than factory bolts and does not drag the block threads while torquing. It belongs in any engine seeing boost or high rpm.

For a stock rebuild, OEM main bolts and OEM rod bolts are correct — and both are replace-on-assembly parts. Do not reuse them.

Also here: street rod bushings, the crankshaft key set and brass freeze plugs, a sensible upgrade over steel while the block is bare.

Harmonic Balancer — and the Leak It Causes

The elastomer in the factory balancer deteriorates with age, costing performance and letting vibration through to the crank. The OE replacement is the fix.

If you have a persistent oil leak at the balancer, stop replacing the seal. The usual cause is a groove worn into the balancer's seal surface, and a new seal riding in that groove leaks immediately.

The Seal Saver is a repair sleeve that presses on to give the seal a fresh smooth surface. There is an equivalent Seal Saver for the rear main, plus the OEM front seal and balancer pulley bolt.

Build Combinations That Work

  • Stock rebuild — Street Performer pistons and rings, standard bearings, OEM bolts. Start at Rebuild Kits.
  • Naturally aspirated performance — 10.0:1 forged, coated bearings, main studs, factory rods.
  • Boosted, serious — 8.3:1 forged, coated bearings, main studs, upgraded rods, matched valve train.
  • Race, naturally aspirated — 12.5:1, Crossbeam rods, race fuel.

Tell us the power target, the fuel and what the truck does and we will put the combination together with you.

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