Generation IV Internal Engine - 7000rpm camshaft?

What kind of specs should i be looking for if I want to rev around 7000ish with my LSX 427 build. Or should I not even rev that high, I have heard the L92 intake quits flowing around 6200ish. What do you guys think?

If you could be more specific about your whole setup that would help make recommendations more accurate. Vehicle type, weight, trans type, rear gear ratio, header size/exhaust system, intake system would be a good starting point. Driving style will also be helpful.
To help get a 427ci engine rev to over 7000 you should consider running the LS7 heads instead of the L92s due to the improved rpm capability of the LS7 intake manifold.

Good luck with your build.


Richard :)

If you could be more specific about your whole setup that would help make recommendations more accurate. Vehicle type, weight, trans type, rear gear ratio, header size/exhaust system, intake system would be a good starting point. Driving style will also be helpful.
To help get a 427ci engine rev to over 7000 you should consider running the LS7 heads instead of the L92s due to the improved rpm capability of the LS7 intake manifold.

Good luck with your build.


Richard :)

Richard..... which do you think will RPM higher....

LS7 Carb Style or Composite?

I've seen both setups make power over 7000rpms on 427ci engines. Also I've flowed both style intakes and they both have similar flow capacity. I guess that leaves the runner lengths to determine the actual power peaks.

Richard :)

I've seen both setups make power over 7000rpms on 427ci engines. Also I've flowed both style intakes and they both have similar flow capacity. I guess that leaves the runner lengths to determine the actual power peaks.

Richard :)

if that is the case.... than a shorter runner normally will peak higher... it will move the powerband up....

now what skews this is when you enlarge the port diameter of the runner and increase its volume...... I bet that offsets things just a hair huh? :confused:

I'm trying to get the truck down to like 4100lbs. I got 4:10 gears with a M12 T56 and 265/75/16 tires. The engine is a 4.125 bore and 4" stroke. Running 11.5 compression and looking for 1 7/8 long tubes. I like the idea of the LS7 heads and intake, but I can't justify the huge price difference between those and the L92's. I will probably put 150 miles on per week.

if that is the case.... than a shorter runner normally will peak higher... it will move the powerband up....

now what skews this is when you enlarge the port diameter of the runner and increase its volume...... I bet that offsets things just a hair huh? :confused:

Generally true Mike. Runner lengths can be used as a tuning tool to optimize power along various parts of the engines rpm range. Runner cross sectional sizes can have differing effects due in part to the enertia the air mass (laden with fuel) contains.

Richard :)

What kind of specs should i be looking for if I want to rev around 7000ish with my LSX 427 build. Or should I not even rev that high, I have heard the L92 intake quits flowing around 6200ish. What do you guys think?

For this motor, less than .650 lift, Higher lift on exhaust, longer duration on exhaust. The durations are up to you depending on the power curve you want. Would not wish to compare to other intakes.