Head swap header info??

Question

Hey group, I have ordered a 4.0 head to go on my 84 CJ7 4.2, Manual Trans play toy... I need to find a header that will be compatible with this swap. Has anyone out there done this swap and, if so, which header or manifold did you use. I've read Tim Weavers article on the swap but info on the exhaust set up is pretty vague and not really applicable to my 1984 model. (Bill, if you could step in here it would be greatly appreciated!) Thanks in advance for any and all replies... Charles

81 DJ5L
84 CJ7
92 Cherokee

L.W.( Ãill ) Hughes III · Accepted Answer

This just a Guess, but the difference is the relocation of thesmaller intake ports on the four liter, and that the exhaust ports arein the same position, making it possible to bolt your old cast iron on.But why not buy the newer tuned tube headers?         God Bless America, Bill O|||||||Omailto:

Carl · Answer

I would think you could just buy an aftermarket 4.0 header and install that.Carl

Simon Juncal · Answer

You need a 4.0 header, the cheapest are on ebay Stainless steel for around 50 bucks, these are just direct rip offs of OEM tube header with the accourdian flange to eliminate the cracking problem on the long tubes.

You then need welding skills or a muffler shop to do your collector pipe, your old one more than likely wont be even close to the header's output. The 4.0 collector pipe (or "down pipe") is on the wrong side and routed differently from the YJ and most likely the CJ.

Rich · Answer

I did the swap. It's well worth it. Use a 4.0 exhaust manifold or aftermarket header. Boorla makes one that will bolt right up. You have to call them and tell them what your doing and they will take allot of your money in exchange for an excellent product. I was a cheapwad and went the cheap route with a $75.00ish aftermarket header. I bolted everything together then went to the local muffler shop where they made me a collector pipe to go to the muffler. Don't forget to get the O2 sensor installed if you need one. The muffler shop charged me something like $50.00 for the pipe and installation.Doing the head swap was well worth it. CAUTION! Don't just throw the old rods and rockers back on before measuring the whole shooting match. I had to have custom pushrods made. It was another $100 at Crower cams in San Diego. They were real helpful. They gave me an adjustable push rod and a solid lifter to use for measurement.My Power and economy are way better than before. I gained about 3-5mpg...

Head swap header info??

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