Will a 99 Dual Pattern Cam work on an 87 Renix??

Well, I've been hearing some noise in my motor latly (4.0s are noisy, but this tap,tap,tap is deffinatly not normal) and I'm pretty sure I have a stuck valve (I tried the old paper over the exhaust trick, and the exhaust is sucking the paper in, so I've got a stuck valve), This sounds like a lifter problem, and its a good practice to replace the camshaft if your going to replace the lifters. So I was wondering weather a newer Dual Pattern (99+) camshaft would fit and work well in my 87 Renix 4.0. Dino Savva mentioned on his site that because of the poor exhaust flow, Mopar gave the 4.0 a dual pattern cam in 99 that would make the exhaust valves open better. If I'm going to go through the trouble of replacing the cam, I might as well get one that will make my motor run a little better, and I figured that some one on here would know weather one of those newer cams would work good on a Renix. Let me know what you guys think.

If you are having a noisy lifter (when warm and idling with low oil pressure) then it is time for a rebuild or a rebuilt engine. If the noise is constant from cold startup you need to do a compression test and then remove the valve cover and check for broken/worn rocker/pushrod/valve spring, etc. On an 87 you are most likely due for a complete rebuild - lifters start getting noisy at 175,000+ miles.

Ditto on what Rob said. A compression check on all cylinders will reveal if there's a leaking valve or leaking rings. I suspect that an engine rebuild is on the cards and that being the case, you could invest in an aftermarket cam/lifter package. If you're looking for more torque at low/medium rpm, go for the Crane 750501 cam. It's better than the '96+ OEM cam and it strikes just the right balance on the 4.0.
Then again, you could rebuild your engine into a stroker. It won't cost you much more and you'll love the performance gain.
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Dino's "Mean Green Machine"
1992 XJ Laredo 4-dr - 12k miles on 4.6L HO Stroker AX15, NP231, D35c, D30

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