What it does is let in lots of hot engine air in. It sounds super... but there are not really any gains to be had.

Especially the Rochester Q Jet carbs.. 850 CFM rating.. They sounded like a vaccum cleaner!

 

Carbs? You mean carbs like diet? Does my engine look fat in this truck? Ha ha.

Yeah I know about the flip lids and things like that. Not so much about carbs but enough. My earliest memories was my dads Nova. Dual glasspacks with no cats. Air shocks in the back, (a must lol.) Very motivated 350. 29 inch slicks in the back and I think 14 or 15's in the front. Jet black outside blood red inside. That thing was AWESOME. He said he sold it to take care of me, but he could have kept it. We could have worked on it together, but oh well.

If I had a car like that I would probley lose my license anyways. If you want to get younger peoples goat, tell them about "burning out" the packing of older glasspacks with kerosene or gas. That'll them. Ha ha most of them never heard of such a thing and if they have it's the rev it up and spray water up the pipe method.
BTW I'm 23.

 

On the 60 degree tbi engines the stock snorkle is rather restrictive and flipping the lid has been proven on a dyno for a couple of extra ponies. Taking the silencer out of the air inlet tube is something else that could be done. Swapping out to a 4.3 breather and air tube with also helps.

This only applies to the TBI engines since the old 2.8 carbs had a square inlet and nothing will swap out with them.

 

I noticed that square inlet too and my idea is to cut the bottom off of the stock air cleaner for both a 4.3 and the 2.8 then drill some holes and attach the intake from the 4.3 to the base of the 2.8 set up and there you go. Haven't done it yet myself but it sounds like fun.

 

Almost cost my dad a $500.00 fine by a judge who didn't like him screwing around with the "smog" device on his carbed big block Chevy. Don;t think the temp device works too good that way. You won't notice any difference in performance. Like has been already said "Been there done that".

 

This makes me realize I'm not the spring chicken I've always thought I am...lol

 

WOW, we have some educated youngsters on this here forum. It is actually nice to see. I will not soon doubt what some of you guys know. I tip my hat to you.

 

Man i remember my first v-8 when i was 15, A 1987 buick regal with a 307 crate, My friends dad flipped my air cleaner lid i ask "why would you do that", He says Makes your 2brl sound like a 4brl. I always did Love that little trick

 

you said it!

i actually had some kid ask me what kind of supercharger i had on my '92 Jimmy once, 'cause i opened it up coming across the yard @ his work.

i just looked @ him and smiled. dumb ricer kids will believe anything.

not that i ever confirmed/denied that there was one, but the truck hauled *** enough to make him think twice.

 

yup, sounded mean as hell on my 80 gm seirra grande 4x4 with the 350... especially when I compression braked!!! wow people from 3 blocks away would turn to see wtf that was lol
good thing i had the trans shift kit.
but onto the OP, if you have PCV lines that run to the air cleaner you're defeating them by opening up/flipping the lid