We were recently alerted to a social media post on Indy Cylinder Heads’ Facebook page showing a new AMC build, which brings out all kinds of nostalgic muscle car enthusiasts. The photos displayed a 500 cubic inch AMC 401 aluminum block and big port 380 cfm aluminum heads with a big-volume single-plane intake combo that will make up to 900 horsepower the all-natural way (without power adders).

Indy Cylinder Heads has been manufacturing aluminum blocks and heads for AMCs for nearly three decades. The Indy Maxx aluminum blocks feature ductile iron sleeves, splayed billet main caps, and a redesigned oiling system. You can also upgrade to roller cam bearings. A fully machined block only weighs 115 pounds.

While we initially thought it was something new from the folks at Indy, a phone call to the head engine-builder Kenny Lazzeri revealed that it is a combo they’ve had for years – 28 years, to be precise. Lazzeri says they started offering the aluminum high-flow heads back in 1993 and the 360-401-based aluminum block shortly after.

He also says that of the nearly 5,000 engines he’s built in his career at Indy, not many AMCs have been built, because cranks are challenging to find. “We haven’t built that many 500-inch AMCs because cranks are so hard to come by,” says Lazzeri. “So we do them when we can. But, I’ve built maybe 50 to 60 AMC Motors. Not that many.”

Indy offers two sets of AMC heads. The 401-1 has a 2.19-inch or 2.25-inch intake valve but with a difference in exhaust port shapes. The 401SR has a dogleg port for AMC headers, but he 401-1 has a Chrysler 440 exhaust port.

Admittedly, Lazzeri says the AMC stuff isn’t as good as what they can do with their Chrysler packages, but it’s pretty nice for the nostalgic racer and AMC lovers. “It’s good, far as the AMC world goes,” he quips. “The basic bracket engine makes between 800 and 850 horsepower. Then, if you want to get after it with a light ring pack and titanium valves, you can get it into the 900-horsepower range, but that’s the most I’ve gotten out of it.”

The 500-inch engine Lazzeri is currently building for an undisclosed customer will go into a nostalgia bracket car. “It’s just a foot-brake bracket car,” he notes.

But that engine only weighs 397 pounds with water and oil. So that’s one of the best parts of that engine. — Kenny Lazzeri, Indy Cylinder Heads

For big power bracket cars, Kenny Lazzeri of Indy Cylinder Heads uses a high-rise single-plane intake for a Dominator-style carburetor. The engine combo is expected to produce 850 horsepower from 500 cubic inches, naturally aspirated. We dig it.

Indy Cylinder Heads makes two different aluminum heads for AMC packages. They have a hybrid head, which is a 440 Chrysler cylinder head made to fit an AMC block with a Chrysler exhaust flange pattern. The other cylinder head Indy offers is more stock, in that it uses AMC exhaust ports.

It’s more like the original head with a dogleg exhaust port for an AMC header. The intake volume is a lot larger. So it can flow decently in the 330-340 (cfm) range.  — Kenny Lazzeri

“It’s actually a legal Super Stock cylinder head. All of the top Super Stock cars run these heads. The 401-SR is what we call it. And then the other one is basically a 440 that we made fit an AMC block.” The 401-SR is a replacement-type aluminum head for AMC V8s and features a modern high-quench heart-shaped 61cc combustion chamber and a generous 235cc intake runner. Any AMC intake manifold can be used, but if you want more performance, then Indy’s 401-3 single-plane intake fits the bill.

“We make all types of intakes, including low-volume, big-volume, tall-deck, and short-deck,” says Lazzeri. But the one they are currently building is a 401-3 single plane Dominator-style intake. Lazzeri says that with this setup,  guys can drop them in a Jeep and get 550 horsepower out of the box because they bolt up directly. He notes that the stock blocks are drying up, which is more reason for an upgraded aluminum block. “You can drop an AMC in any Jeep, and it will bolt right up,” says Lazzeri. “At one point, I built about 100 of these a year, but the blocks are hard to find… or someone is hoarding them.”