Intake manifold options for an 81

[jcoats]

I'm looking at upgrading my intake manifold to try to get some more HP. My 81 is stock for the most part. Previous owner removed the cat and added sidepipes. I've seen a few different Edelbrock options (2101 and 3701). I intended on keeping the CCC controlled stock carb.

Any insights are appreciated. Thx

 

[22229stingray81]

I have an Edlebrock Performer intake, however, from what I understand, power increases are negligible. The stock intake is aluminum, and already pretty good. Changing the heads, and a true-dual exhaust are where the big gains are.

 

[Tom Bryant]

Given the RPM operating range of a stock L81 I think you will be disappointed with just a manifold change. Your stock manifold will most likely match the performance of either of these manifolds in the idle to 5500 rpm range. I remember a test way back when the 2101 first came out where a stock Chevy cast iron Q-Jet manifold out performed the Edelbrock in the low to mid rpm range and was a match in the upper revs. The only benefit was appearance and weight for the alloy manifold. You already have an aluminum intake that is probably better than the old iron ones or at least a match. The alloy intake and magnesium valve covers were put on the L81 for weight savings mostly.

With the exhaust already opened up I feel you would get more bang for your buck with a camshaft change. Keeping the CCC system will require careful selection of the right cam for it to be happy with the computer. The best way to do that is to get a recommendation directly from the cam manufacturer, especially if you don't want to do any other mods. They know better what will match than any number of online forum opinions unless you are going to duplicate someone elses success part for part.

Tom