'69 396, 268H, 650DP, Exhaust manifolds with chambered exhaust. I am running the stock snorkle air cleaner. Will I really see a difference if I use an open element air cleaner instead?

Yes, unless you duct the snorkle to the front of the car, kind of like a "ram air" effect. I run an open element K&N filter 14"x5".

This is what you need if you want to run an open element:
http://store.summitracing.com/partdetail.asp?part=SUM%2DG3000

it has no logo,looks identical to the factory open element air cleaner,and its alot cheaper.Order some 396 crossflag/tubojet decals from your favorite resto supplier and off you go.
You'll just need a push in breather for the pass. side valve cover.The air cleaner base can even be painted black to look "correct"

The performance will improve some, not sure how much. The intake noise will make it FEEL a whole lot faster. smile.gif

I have tested the same thing with my 68 396.
The short answer is no.
The longer answer is I have the original 325 horse rebuilt with a Comp Cam 268H, exhaust mainfolds,closed element air cleaner,original carb, dist., bla bla.
I first had the closed element housing with an A/C Delco filter then tried an open element with a Fram paper filter. I couldn't 'feel' any difference.
I went back to the closed one because I liked the factory look better. :cool:
Now it's out an a 502 is in. :D

every engine is different.........the one thing i would not do is run an open element without the supply of fresh cooler air.......i would use it with some kinda cowl hood or hood scoop sealed of from the engine heat........i wouldnt just run an open element under a hot hood.........

Came across this by accident, but I am giving serious consideration to one of these units. www.ramairbox.com (http://www.ramairbox.com)

I'd buy a reproduction factory style open element.

Thats what I run on my 68, and the factory style drop base will let you run the breather hose to the air cleaner assembly, I'm also running a 4" K&N filter.

I've never tested a snorkle compared to an open element. But I have tried paper, vs. K&N, vs. just the bottom with no top, or filter.

The K&N was worth about a tenth, and a mile per hour, the no filter picked up another mile per hour, but no time improvement.

I don't think you can feel a tenth of a second, in the seat of your pants. I doubt unless your really good, or have a lot of experience, that you could detect 5 tenths of a secound.