Looking for advice - 258 smog/engine swap

[boomer75007]

I had an earlier post for my 258 Engine having "no spark".It turns out my ECM crapped out on me.I tried the "Nutter Bypass",and got it running again.But now Im being told that the carb is dumping too much fuel,and can't get it to pass inspection.My ultimate goal is to put a V8 engine (304) in it.I have found an AMC304 engine with approx. 30,000 miles on it.The guys asking $550.00 for it (complete).Do you guys think I should drop another $200 or so in my 258 to try to pass it......or try to get the V8,and move on.Im not really sure how much extra it will cost to switch out.But I was thinking about offering less for the 304,and see if he might be interested.Any advice????

[Giffer]

i dont know what its going to take you to drop the 304 into your jeep, but if you are all hell bent on dropping it in then why are you still messing with your 258. yeah your jeep will be MIA for awhile but in the long run you would be happier. and the 200 is a good start, or aleast would come in hand when you drop the v8 into her.

[Dukes69]

Well, if your ultimate goal is a V8 then I say dont spend and more time or money on the I6 and just jump into the 304. If Rick is around I'm sure he might have some ideas.

[rick]

Why do you want a 304? Would it even pass smog considering the 304 was not available in the CJ in 1986? I'm not sure about TX, but it would not be legal in CA. If you want to get some extra power and some additional reliabilty, why not swap in a 91-95 4.0L and drop the carb altogether? You can get junkyard 4.0L's complete with all the wiring and junk for about what you'd have in the 304. I guess it depends on how much you want to spend. Swapping in a junkyard 4.0L will cost you somewhere in the neighborhood of $600-1000 in extras, depending on whether you buy the conversion wiring harness if yours is getting tired (mine sure is). At a minimum you need the crank damper and CPS kit to relocate the CPS to the front of the engine, fuel pump, speed sensor, and fuel lines.

My best advice on passing smog with what you have is try making the carb leaner and see if it will pass... Other than that, you're stuck with a new ECU.