Stick with the 232 or go with the free 258

Here is the situation.

I have the stock 232 in my 72 CJ-5 and a friend is offering me his 258.

The 232 runs well, but seems a bit underpowered with its single bbl carb and my heavy hardtop weighing it down.

Here is the 258's history:

Before I ask him to haul this engine back from his hometown (we both go to school at Virginia Tech), I wanted to get the opinion from more experienced Jeepers.

I was going to install fuel injection and a new to me distributor on the new to me 258, but I believe I could install both of those items on the 232, if I got a 2 bbl intake manifold. (Or at least that is what I understand to be correct.)

This is all complicated by the fact that I don't have a garage of my own down at school to keep the engine and would have to have it dropped off with a generous friend or at a garage or storage facility of some sort.

What do you think? Keep the 232 and upgrade to FI and new dizzy?
Work out the details on getting the engine to school and go for the 258 swap?

I have been running this through my mind all day and was hoping someone could offer some wisdom here.

Thanks for reading!

 

if the 232 is running well i'd leave it alone. power difference is not that great and if it aint broke don't fix it. go with the fi on the 232 and have fun.

 

Power difference will be roughly equal to the displacement change: 258/232 - 1 = 11%. The 258 uses a different crank (longer stroke), rods and maybe pistons but is the same as the 232 otherwise.

In 1981, AMC/Jeep updated the 258 to make it lighter and to produce more power. The pre-81 enfgine will have a heavier block, crank (more counterweights), and manifolds. The later engine also uses the terrible plastic valve cover, and your only alternative would be an aftermarket aluminum cover. SHould have smaller head bolts too (7/16" v. 1/2"). The post-80 manifolds are better, and would fit on your 232.

If it were mine, I'd take the 258 for the manifolds and look for a 71-80 258 short block for free or cheap. The carb on the free engine may have been changed to a Motorcraft or Weber 2V, both good replacements for the stock BBD.

 

As always Tim, your opinion and wealth of information is invaluable! You also have a great first name btw.

He said he was probably going to junk the engine if I don't want it. I was thinking that if he does have the manifold and carb, that would be a good upgrade in the meanwhile as I search for the suggested short block. It would also be easier to store in anticipation of the upgrade. Hmmm

 

Unless you have a header, you'll want both manifolds. The intake on the '82 is aluminum and the exhaust is iron. You install them together but they don't bolt together like the earlier all-iron manifolds.