My advice would be to forget the headers entirely. A 350 without headers is still going to motivate your Jeep down the road quite nicely. I too used to have fenderwell exit headers and wound up hating them with a passion. I removed them in favor of a pair of GM Vortec 350 cast iron manifolds that offer plenty of flow with no noticeable loss in performance over the headers. For more info, check out http://www.dirtroad.com/ NV4500 part 2 article, wherever it is....

"I have a 1978 CJ-5, with a 999 to 327 Chevy. I'm in the process of dropping in a 327 Chevy into my Jeep with a 999 tranny. I was wondering if swapping to a T-350 would be better or spending $500.00 to buy an adapter plate is necessary?"

I wouldn't hesitate to swap in the TH-350 transmission. You will still need an adapter between it and the transfer case, so you won't be saving any money. I think the reliability of the TH-350 would be well worth the added expense over adapting your Torqueflite.

"I have a 1984 CJ8, with a 258/T-4. I have an extra 258 I6 and would like to rebuild it. I was thinking of changing the cylinder bore and adding an aftermarket cam. Can you suggest a bore and stroke, also a good cam?"

I can suggest a couple of sources for you to check out. Clifford Performance specializes in 6 cylinder modifications and they have plenty of goodies for the 258. You might also obtain a Mopar Performance catalog for lots of 258 performance information.

"I have a 1985 Jeep Cherokee Pioneer, with a 2.8/5-speed. What do I need to put a 351 Windsor in it and will the transmission work? How much will it cost me?"

While I like the idea of a Ford V8 in a Cherokee, forget it. A Chevy V8 can be placed in a Cherokee for a few grand through the help of Advance Adapters, but there aren't any swap kits available for the Ford engine. Any V8 that you choose to install will chew up your transmission in short order. Include the cost of a new transmission in your swap.

"I have a 1997 Cherokee Sport, with a inline 6 4.0. I have installed high performance wires & plugs. What else can I do to improve power & performance?"

You haven't even scratched the surface of the potential of the 4.0L engine yet. The first thing I would suggest is visiting the Turbo City website at www.turbocity.com. They have lots of goodies for the 4.0L along with typical horsepower gains associated with each item. They also have a turbocharger kit that could really make your Cherokee a screamer. There are supercharger kits available from Rimmer Engineering, www.rimmerenginc.com as well as 4.7L stroker kits from Hesco. I'm sure that any of these companies can point you in the right direction to gain a significant amount of power from your Cherokee.

"I have a 1984 Cherokee, with a 2.5ltr. I'm looking at swapping a tired 2.5 hooked to AX5 trans. Advanced Adapters is expensive. Are there any other engines that bolt up to the the AX5, or do you know of anyone who sells hop-up parts fpr the 2.5?"

To my knowledge, your AMC built 2.5 has it's own bellhousing bolt pattern and is not readily compatible with any other engine.

My advice would be to find a 2.8 V6 cherokee in the junkyard and pull the engine and tranny. It's a little easier to wake up the 2.8 V6 than the old carburetted 2.5's. Since the GM 2.8 was an option in 84 cherokees, they should be easy to find in a junkyard and very inexpensive to obtain. If you decide to stick with your four cylinder, check out www.cliffordperformance.com or buy a Mopar Performance book from your nearest dealer.

"I have a 1980 CJ5, with a 258/manual. I have decided to swap out my 151-I4 for a 258-I6. I would like to buy an old 258 and rebuild it. This engine will be for highway and offroad use about 70/30. Could you point me in the right direction on which components I should be switching out to get the most out of this engine and tranny combo as this is the first time that I have tried something like this and only want to do it once (famous last words). I have got the time to do it right since the 151 is still runing (sluggishly) and am going to rebuild the 258 as time and money permit. I plan to switch the tranny and transfer case out at a later date if it will not hold up to the new 258. Any suggestions on a total rebuild would be appreciated such as cams, manifolds, carbs, etc. The jeep is 100% stock now and will have to comply with any Texas Emissions laws if any apply."

Clifford Performance (www.cliffordperformance.com) could easily be considered one of the better sources for performance parts of any inline engine. My concern is that you have stated you will need to have your Jeep pass a sniffer test. You may want to speak with the people at Clifford as well as state of Texas to determine exactly what modifications would be considered legal.

Have you considered making the leap into fuel injection? Since you will have to purchase a new engine anyway, why not the 4.0? It is much more powerful than the 258 in stock form. The added benefit of fuel injection over carburettion will not only show up during daily driving, but at the emissions test as well.

Concerning your transmission; swap it. You most likely have the SR4 aluminum case 4 speed. It's fine with the four cylinder, marginal with a stock 258, and will slowly die with a 4.0L. You have tons of options regarding transmission swaps. If you'd like to stick with the factory offerings, you can get a T-176 four speed from a 80's 258 powered CJ, or use the AX-15 5 speed from late model 4.0L wranglers. For very heavy duty transmissions, you can use virtually any full size truck four speed in your Jeep. The only drawback being the expense of custom adapters to complete the assembly. Either way there is no need to change the transfer case, the Dana 300 works fine with heavily modified V8 Jeeps.

"I have a 1979 CJ5, with a 258/t150/dana20. Want to swap t-150 for a 4-speed. What is a good, inexpensive, simple swap? Whant to keep the 258 6cyl and the dana20 if possible."

It may take a lot of searching, but the easiest swap would be for the factory offered T-18. These were offered with the 258/dana 20 combination and would eliminate the need for expensive adapters.

"I have a 1995 wrangler, with a 2.5l and ax5 trans. I am interested in dropping in a 4.0 6 cyl, and was curious about all that is involved. A trade-in is not an option as I have spent too much time/money on other areas of the Jeep and don't want to start from scratch (suspension lift, 33's, loads of other things). My main concern is emissions equipment and what else I would need on top of the engine and ax-15 trans."

My advice would be to find a junkyard 4.0 from a similar year wrangler and gut everything under the hood. Take everything from the radiator back to the firewall, and don't forget the ECU. The more factory parts you can get your hands on the cleaner and easier the installation will be.

"I have a 1989 Jeep Cherokee XJ Limited, with a straight 6 4.0 auto. I am in the begining works of putting a Chevy 350 four bolt main in and I was wondering if you know of any problems I am going to run into and what kind of mods I am going too have to do. Do you know if I can use my stock radiator to cool it and be enough or if I am going to have to get a different one, and if so do you know where I can get one. I know I am going to have to change some stuff but any information you might have or things you know I am going to have to do would be greatly appreciated."

According to Advance Adapters, a 3" suspension lift is mandatory for oil pan clearance when installing a small block chevy engine. If you've already lifted your Cherokee then that's not an issue. I suspect cooling will be a major problem. The stock cooling system on 4.0 XJ's is marginal to begin with, some sort of larger radiator or auxiliary cooling will be needed. You are probably also aware that a new transmission will be needed. Before picking up any wrenches, I'd suggest discussing your ideas with Advance Adapters to discuss availability and cost of the parts you will be needing.

"I have a 1989 Cherokee Laredo, with a 4.0/Auto. Do "high performance" ignition systems do much better than stock? I'm considering a Jacobs Electonics package (wires, coils, etc) but I'm not sure if they really do get one better gas mileage and performance.

Any facts out there?

(I heard about Jacobs while researching Splitifre plugs which the FTC has banned from advertising better mileage and performance as their claim is unsubstantiated.)"

Of all of the high performance ignitions available, the Jacobs is the only one I would consider. We are using Jacobs systems on both our Project TJ and Scrambler. The difference on our (at the time) carburetted scrambler was huge. It ran much smoother and started much easier. I have not noticed any mileage gains, mostly because the V8 is just too much fun. The big improvement came in the driveability of the engine, it sounded better and idled perfectly smooth.

"I have a 1995 Jeep Wrangler, with a 2.5 L /five speed. I am going to install a 3.0 litre Mercedes Benz turbo diesel engine in my Jeep. I would like to find a Unimog transmission (19 speed) but this might be hard to find. I would like to know if you have heard of anyone installing a diesel to a Jeep 5-speed (adapter plate) and if any substantial modifications need to be made to the fuel tank. "

I'm very intrigued by your choice of engine swaps. I'm sure in order to use the diesel with a Jeep tranny a custom adapter plate would have to be fabricated. You might try calling the usual adapter manufacturers and maybe they will be able to point you in the right direction. Please keep me informed of the swap, and take lots of pictures!

Any readers know where a Unimog transmission can be found? If you can help, E-mail grant@dirtroad.com.

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