AMC 360 Limited RPM?

I think the problem in this case is restriction of getting air or fuel into the engine at WOT.

I think the OP said his vehicle has a manual trans. In which case the transmission (theoretically) is NOT a limiting factor.

Rpm is a function of air flow. The limits, then, are restrictions on either the intake side or the exhaust side (assuming fuel and/or spark aren't going away at rpm).

The cam will determine how much power you make and at what rpm, but a cam such as an Edelbrock Performer will NOT make your engine "throttle out" before 5000 rpm...as long as your intake and exhaust aren't restricting engine operation. Now, an SP-2P intake, or a Holley Z-series intake, with their small runners, might keep the rpm's down due to their high-velocity, low volume design. But your average factory or aftermarket intake won't.

So then, if you eliminate fuel flow, spark, intake manifold and exhaust system as the problem, and if your engine has a healthy valve train and pistons/rings...where is the restriction that keeps your engine from turning 5 grand?

Congratulations. You have your answer.

If the other systems aren't up to snuff, and you're sure you haven't wiped any cam lobes, the process of elimination takes you to your answer.

DaemonForce wrote: I was going to say, unless he's out to make the OTHER kind of 360, which is similar to the fat bore skinny stroke recipe I have in mind for my first V8 build, none of this action really makes any sense. Assuming the typical WPC treatment and other requisites are being made to get this thing survivable at high winding RPM, it's just not going to hold there. The 5K RPM and cam aren't the stumbling blocks here, it's getting more air and fuel into each cylinder to make more power and even then, we're still looking at a possible dead zone or whatever is being described because this engine makes the majority of its power at lower RPMs. If you want to make a high RPM AMC screamer, here's what you do: Start with a 401 block. That's it. That's really all there is to it. I don't know if 9.2 pistons would be right for that new geometry but assuming you want the cam to come alive later, custom grind it .450/.450 with -8, 10, 30, 0 and retard it 2º for maximum effect. Torque curve is ~400 flat up to 4700 and power should be 200 at cruise and will peak around 5500. It's a bit screwball but good for scaring the JDM kids on weekends.

Alrighty now.