Why Every Head We Build Starts on a Toyota Casting

We will be blunt about this because customers ask every week.

After testing numerous aftermarket head castings, we concluded that the stock OEM Toyota casting is far superior to any of them. It is the only casting we use in our own cylinder heads, and we have never had an issue with one. It costs more than the aftermarket alternatives, and we buy it anyway.

Bare castings are available if you are building your own: 8-port and 4-port.

Port Count First

Everything on this page splits on whether your head has 8 intake ports or 4. The earlier engines use the 8-port head and the later ones the 4-port.

Do not order from the year alone — count the intake runners where the manifold meets the head. It takes ten seconds and it is the only answer we trust. If in doubt, send us a photo.

The Three Stages

Stage 1 — the replacement head

A quality replacement built on a brand new Toyota casting with all new valve train components installed. This is the head for someone whose original is cracked, warped past machining, or has dropped a seat — a better-than-new replacement rather than a performance part. Available 8-port and 4-port.

Stage 2 and Stage 3 — better than stock

Both are genuine upgrades over the factory head for a performance engine, and both are designed to work with our Stage 1 or Stage 2 camshafts. Stage 2 in 8-port and 4-port; Stage 3 in 8-port and 4-port.

Valve Springs — Buy by the Numbers, Not the Name

Spring choice is what decides whether a camshaft survives. We publish the actual pressures so you can match them:

  • Street Performer — 53 lb seat at 1.44", about 145 lb at .450" lift. Mildly built naturally aspirated or low boost 0-10 psi. Use with our Pro series or Stage 2 camshafts.
  • Dual spring set — 75 lb seat at 1.4", 215 lb open at .450" lift. A must-have with bigger lift cams and higher rpm, naturally aspirated or low boost.
  • Pro HD dual spring set — 100 lb seat at 1.400", 225 lb at .450" lift. High rpm and high boost.

Matched spring and retainer kits take the guesswork out: Pro Dual and Pro HD Dual. Both work with stock cam buckets or our shim-under buckets.

Retainers

Street Performer retainers are an OEM-equivalent single-spring part (Toyota 13741-46020) and the right choice for a mild engine.

Pro titanium retainers are CNC machined from heat-treated titanium alloy — stronger and lighter, which is what lets a valve train survive high rpm. They will not work with a stock spring or keeper; they are designed to run with our hardened keepers and spring kits. Also sold individually.

Cam Followers — Match the Bucket to the Camshaft

This is the part people skip, and it is the reason some big-cam builds wipe a lobe.

A larger camshaft profile needs a larger diameter follower, or the lobe runs off the edge of the bucket. Our shim-under-bucket followers are designed using CATIA and finite element analysis for endurance, road and drag racing loads.

Order by camshaft stage:

  • 31mm — Pro, Stage 2 and Stage 3 camshafts. Also as a kit of 16.
  • 34mm — Stage 3 and Stage 4 camshafts. Also as a kit of 16.
  • 35mm — Stage 5 camshafts.

Complete Valve Train Kits — Master or Mini?

These bundle every compatible part so nothing is mismatched. The difference is the buckets: Master kits include the shim-under-bucket followers, Mini kits do not. Buy Mini if you already have the right followers.

Race Details

On billet race motors we block off the water passage at the back of the head with the water block plate kit, with a replacement O-ring available for the billet water plate that eliminates the thermostat housing.

When fitting any head, the head-to-block dowel pins (Toyota 90253-15016) align the gasket and head properly. They are sold individually and they matter more than their price suggests — a head that is not located by both dowels will not seal reliably however well it is torqued.

Head bolts, studs and gaskets are on Rebuild Kits, Gaskets & Seals.

Building a head and unsure how the springs, cam and followers should match? Tell us the camshaft and the rpm target and we will spec the valve train around it.

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