4.0 carburated intake manifold

1980cj5 · Jan 27, 2010

I am thinking about doing a 4.0 head swap onto my 258. I am trying to find a carburated intake manifold that will fit on a 4.0 head, so that I can avoid all of the hassles of EFI wiring. But I can not find anywhere that sells a carburated 4.0 intake manifold. Has anyone found somewhere that sells 4.0 carburated intake manifolds?

JOOP · Jan 27, 2010

I don't think there is one. Have you tried Ofenhuaser intakes?? I think thats the name of the company.

zemiller · Jan 28, 2010

doesn't the 258 manifold fit the 4.0? I thought the manifolds interchanged on those? I'm not sure, more of a V8 guy myself, but I thought I read that somewhere.

zukkev · Jan 28, 2010

Why do the swap if your not gonna utilize the injection (biggest reason for this swap!)???

1980cj5 · Jan 28, 2010

I am almost positive that the 4.2 intake manifold will not work on the 4.0 head the main reason being that the 4.0 has round ports and the 4.2 has square ports. I wonder if I could I could just get the 4.2 manifold machined? Does anyone know if that manifold machining would be possible?

It would be nice to have the FI but I dont want to screw around with the FI wireing and sensors. The main reason that I want to do the swap is more power, most people say that just the headswap is atleast a 40HP gain. Also I would much rather work on a carburator than an FI setup, and a truck avenger carb works just fine on hills.

1980cj5 · Jan 28, 2010

Would it be worth it to just get the 4.2 head ported rather than doing the 4.0 swap?

boardbysled · Jan 28, 2010

Do a stroker

JOOP · Jan 28, 2010

1980cj5 said:
Would it be worth it to just get the 4.2 head ported rather than doing the 4.0 swap?

Yes:awesomework:

jimijam19K · Jan 29, 2010

The wiring isn't that hard. Get the harness and I can have it thinned and labled in no time. The bigger headache is modding your bellhousing for CPS or getting butt-raped by HESCO for there CPS crank damper as well as making the Delco alternator externally regulated so the PCM doesn't throw code 41. You can run a 4.0 head carbed though I don't remember the details. Check here, www.cjoffroad.com