Any idea where I can find a cheap new one or a decent used one?
The picking yards have plenty.
Single barrel manifold: Any old Jeep or Hornet.
Twin barrel: Any mid-life Jeep, Concord, Spirit, Eagle...
As far as fuel injection goes, you can get the AMC manifold off of any MJ Jeep. The Chrysler comes off of every Jeep that came afterwards.
If you get stuck aND CAN'T FIND ONE, LET ME KNOW. i HAVE A FEW. (dang caps lock...)
AMC went to Aluminum in '82, all earlier iron sets bolted together, the aluminum have a separate EGR tube instead. You can find them in YJs up through 1996, the one's with the rectangular headlights. They all interchange on the head, but you'll need a couple of brackets if you go from one style to the other, a few accessory bolts moved.
Even the auction site and Craigslist have them, form time to time. They're pleantiful, no one should charge you too much for one.
YJ Wranglers after 1991 were 4.o HO with EFI, so any YJ after 91 won't work for a carb. The '87 to 91 YJ would be an aluminum 2barrel CarterBBD carb intake for the 4.2.
Offenhauser and Clifford have 4barrel intakes for the 4.2, but a stock 4.2 intake with a good MC2100 carb adapted to it is the best bang fer the buck for a stock 4.2 engine.
Quote from: txjeeptx on February 06, 2012, 01:38:25 PM
YJ Wranglers after 1991 were 4.o HO with EFI, so any YJ after 91 won't work for a carb.
I forgot about that, but I knew they did use the 258 longer in the YJ then any other vehicle.
'90 was the last year for 4.2 in anything US built.