I had the intake manifild on my 84 L69 cleaned and i was suprised when i lifted it off and i noticed it was aluminium, it is a GM manifold, so my question is, did this manifold come with my car or did a previous owner just take it off a corvette or somethin?

Whether it came with the car or not, its still a GM manifold but it is aluminum so what improvement gains could i expect from a new edelbrock performer manifold?

 

AFAIK thats the stock manifold for H.O. cars.. I wouldn't expect gains from a proformer as its pretty much just a stock replacement manifold.

 

except the 180degree firing order. and cleaner runners.

 

So is the stock manifold.

 

my bad

 

Folks like to argue this one.

But the magazine builds I've seen where they use an Edelbrock Performer to replace the LG4 intake, which isn't exactly like the L69 intake in every case, they've gained in the neighbourhood of 20 hp.

 

that is with full exhaust first. right?

cuz i myself have this new performer intake.. yet to be installed lol.. but i still run stock exhaust for the time being, though it is the next step.

 

US-delivered V8 cars had aluminum manifolds. Canadian LG4's apparently got cast iron, but L69's were aluminum.

I've never had a Performer manifold. Going from the stock LG4 (same as L69) to the GMPP manifold when the engine was otherwise stock gained about .05 sec in the 1/4. Maybe. Hard to say because of other differences (such as density altitude).

The stock aluminum intake manifold is just about the last thing to change out to improve performance on an LG4 or L69. The last thing would be the carb.

 

 

I disagree. The Performer will gain you almost nothing over the factory aluminum intake. However, the Performer RPM will make a noticable increase - like night and day. Been there, done that. Don't waste your money on the Performer.