Need Advise on Air Box and Cowl Vent - Is it Optional?


Crazy Cajun
I am in the middle of a complete frame off resto-mod of my '84 CJ-8. During the disassembly, I broke the top ducting of the air box and it's not repairable. A used one on Ebay is $50 - $100.

My question is this - Do I really need it? I'm rebuilding the lower portion of the box, so I will have the capability to throw heat at my feet or through the windshield defrosters. I've already bought the bigger motor for that upgrade. However, I don't see a reason to ever actually need the capability of the fresh air ducting. If I'm not running the heater, then the windows will be down or more likely, the entire top and doors will be gone. I'd rather put a blank where that cowl vent goes and call it good. Less chance of getting rain in the cab.

I've also installed a 5.3 Vortec, so there's a good chance that I'll have an AC system one day.

Just for the record, the cables that operate the fresh air system on my 1981 CJ-8 broke 10 years ago. I have heater capabilities but nothing else. I've never missed it.

Any reason I need to spend the time and money on another upper box thinking that it'll never get used?


CJ-8 Member Member
DB I'm down here in the swamp myself and never use my vent either. I can't say much air at all comes in through there. My top is off 361 days a year so all my ventilation comes in that way.


Scrambler Junkie
Without the outside air your windows will fog up. I tried putting a plate over where the vent grill was, on humid rain days and winter days was constantly wiping the windshield and door windows. If you don't replace it you will have to seal off the vent to keep the water off. It's also a bitch to have to put a new top duct. if you are staying with the stock heating unit it's well worth the investment. On my cj7 I put the vintage air system in. It doesn't use the air vent. Will be interesting when I start driving it in rain (has seen rain as many time as you can count on your fingers. It would use the a/c portion to remove the humidity. I haven't installed any a/c (outside of the climate control unit) yet. Plan on that in a few years. I'll probably have the fog problem again.


Scrambler Junkie
I'd say it's probably not needed if you have been getting along without the vent for 10 years, but I'd think that deleting that system would reduce resale value.

Personally I couldn't live without the vent (especially the "crotch vent"), but I don't have A/C. I use a bikini top most of the summer, but in the parts of the year when its too cold in the morning to go without a top yet quite warm in the afternoon, the vent is invaluable ( in my area during October, it can be snowing one day and 80* the next).