Catelytic converter

[1982AMCCONCORD]

OK... so I went and had my old cat tested... nearly completely plugged... had a new cat put on... no air tube... removed the air tube leading up to the check valve. Removed all the charcoal canister stuff too. Bad news is they told me that since the Cat. was so plugged up... it caused me to blow out part of the exhaust manifold gasket at the back of the cylinder head. (SIGH) Now I have a decision to make... do I just fix it or do I go the next step.... 4.0 head... 4 barrel intake and a Renix header? Decisions decisions...

[captspillane]

You can replace the head for very little money. The circa 1992 casting is the best and they are plentiful in the junkyard. In the process of removing the old head the exhaust and intake can be left connected to the exhaust pipe and just pushed off to the side. Once the new head is in you can push it all back with a fresh gasket. Install Grank's 2150 kit on the old intake manifold. Once you have the horsepower boost from the better head and the performance of a 2150 you won't bother with the 4 barrel intake. It will feel like twice the power and will wake your old Eagle up respectably.

The stock intake does not restrict the air from getting to the cylinders until you exceed a certain CFM that your engine will never require. The Clifford intakes are only appropriate for much more extreme engine modifications. They also do not install easily because of thickness issues. I've discarded mine.

Likewise 4.0 headers are nice, but not that nice. Its hard to justify the cost of the exhaust modifications unless your exhaust is already rotted out and in need of replacement. The head will provide a much bigger power difference than the headers will. If you're on a tight budget don't hesitate to get Gronk's kit and the head without replacing the intake or exhaust manifolds. You'll still be quite happy with the end product.

[captspillane]

No you do not. With a 2150 the cam doesn't matter much. Replacing the cam is an important step if you go fuel injection. Even then, I have an MPI kit on my CJ8 with the original cam and I still love the fuel injection performance. It would just be one step better with a 4.0 cam. If you're not removing the engine it isn't worth sweating over. If you still have the old camshaft then you should also retain your 258 lifters and pushrods.

If you remove the engine, then it's worthwhile to replace the camshaft. At the same time you should use 4.0 lifters and pushrods because they're marginally better. The 4.0 lifter is slightly longer than the 4.2 lifter, so it must be mated to a 4.0 pushrod which is slightly shorter than a 4.2 pushrod. Both of them have the same overall length and are interchangeable as long as you don't make the mortal mistake of using a 4.0 pushrod together with a 4.2 lifter.