4.0 head swap and exhaust

[brielly]

My plans for the 4.0 head swap are moving forward. The head is being rebuilt and I have the exhaust manifold and valve cover. My question is.... I have an exhaust manifold from a 95 cherokee which does not have a fitting for the oxygen sensor. Can I have it modified for the sensor or do I need to buy a manifold with the o2 sensor fitting already on it? There seems to be two manifolds available- the one with the 02 fitting for 87-90 4.0 and 91-98 without the fitting. They look very different and I am wondering which one I should use. They also appear to mate up with the exhaust pipe in different places. Has anyone done this swap, which manifold did you use and did the exhaust have to be modified at all to mate up with the manifold? Heres a link to a page with pics of the manifolds. http://www.actionsalvage.com/exhaust_AMC.asp Thanks

[Shaggin' Wagon]

I think I saw them for sale on ebay for around $130 new. I'm gonna have to replace my exhaust, too.

[Ralph]

breilly, have you test-fitted your head and intake manifold yet? You may run into clearance problems with the master cylinder.

The 4.0 head is a bit taller and sticks toward the driver side a bit more, in order to allow a less angular flowing intake runner.

I'm looking for a Clifford intake manifold, which is of similar as the stock 258 manifold, but has bosses to drill for injectors.

As for the O2 sensor, if your exhaust manifold doesn't have a fitting already, it's a simple job to have one welded into your exhaust pipe. Just make sure it's upstream (closer to the engine) than the catalytic converter.

[ June 27, 2003, 09:05 AM: Message edited by: Ralph ]

[brielly]

I will be using the stock manifold and my weber until I can scrape up the bucks for TPI guys fuel injection kit. I believe the stock manifold can bolt to the 4.0 head with little or no trouble.

[Ralph]

I just finished paying off a rebuilt engine with a Weber carb on it. Just how much better will it be than the Carter BBD on my 180k-mile engine?

[brielly]

There is a noticeable difference with the weber on my engine which has been recently rebuilt. Throttle response is much better and gas mileage has improved some.