Question on 258 to 304 swap

Other than the obvious distributor and wires, intake and exhaust manifolds, carb, front exhaust, oil pan, valve covers, and probably the radiator?

I just did this and chose to go with a 258 for exactly this reason. Swap needed almost nothing.

If I was going to bite the bullet and do a V8, I'd do a Chevy small block. Its a bigger job, you'd probably need a new transmission, but you have an engine that still has parts available. Plus you can get one built to whatever HP/specs you want.

Almost did this but when I thought about it the 258 was enough, I drive the jeep easy. I have gone to an HEI distributor and Weber carb, they help a bit.

Thanks, like you I don't need the extra power, just figured if everything was just a direct swap then what the hell.

I know the engine mounts are different. The mount pad also go reverse with the torque hooks on the other side.

I would imagine the rad is different, the 258 rad is barely enough for the 6.

I too would have gone 350 if V8, but stayed with the 258. Once the computer is gone out of the ignition they go pretty good.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail 88 Cherokee 235 BFG AT's

Greg wrote:

What's different?... everything!

Since you don know what all that entails. I assume it's not you personally that would be doing either type of swap.

My 258 does just fine... when it goes, I will rebuild it.

You might check prices at your local Advance... then you could take advantage of the core return.

Well, one block is four cylinders long, and the other is 6, not to mention the different sizes of the respective cylinders.

Nothing will swap, except perhaps the alternator and the power steering pump.

Greg,

I've done this swap twice (259 to 304). I've heard all the arguments about the 350. I wanted to stay in the "AMC Family" though. Another advantage is not having to swap the tranny or mess wtih adapotrs. Makes it easier for those of us less skilled mechanics. However if I did this a third time I would go with a 360 or 401. If you're gonna go, go BIG.

The swap is not really that hard. I would rceommend that you get several different manuals and study (not just read) up on the procedures. The first time I did this I had a really basic set of tools and was able to pull it off.

--Most deffinatly have to swap the radiator. You'll also need new hoses.

--Carb and manifold are different. The fuel line comes into the engine compartment on the "wrong side" after the swap so you have to reroute it.

--Power steering pump is the same, but the brackets are different and HARD TO FIND.

--You can get away with the same alternator, but again different brackets.

--Need all new motormounts

--Wiring is a little different. Make sure your manuals have a good schematic of both the current engine and the one you are swaping in (the year of manufacture can make a difference here).

--Distributor is different.

--Exhaust manifolds are different.

Both the 304s I put in were pre ECM so I can't speak for that part of the swap, I just by passed it. On the second one I used a complete MSD system.

And of course don't forget about EMISSIONS!! This can really bite you in the a** depending on where you live. I just left CA (thank God) but they got a lot of money out of me to pass my Jeep after the conversions.

Hope this helps

Erik

Well all opinions talked me into just redoing mine, thanks for all the advise.

Hum, tempting, freind just bought a 2nd cherokee for parts, 360 in both.

Now you're talkin'... a parts donor for a 360 long block.

JimG