Page 1 of 1

AMC 232 upgrade routes

Posted: August 17th, 2022, 8:18 am
by TinkerJeep
I am new to this forum. Forgive me if this is the wrong board to post on.

I have a 94 232 in the machine shop right now. I am wondering what my options are for upgrading this engine from stock. As far as I can tell, everything on the engine is original. I have researched options such as stroking it with a 258 crank and rods, and putting a 4.0 liter head on it. Trying to keep it relatively budget friendly with room for future upgrades down the road (better intake/fuel injection).

any advice is greatly appreciated.

Re: AMC 232 upgrade routes

Posted: August 18th, 2022, 7:39 pm
by IH 392
According to my info the last 232 was produced in '79?
The only difference between the 232 and 258 is the crank and connecting rods, everything else is identical.
What is this engine in??

Re: AMC 232 upgrade routes

Posted: August 21st, 2022, 6:56 am
by TinkerJeep
Sorry that was a typo. The block is a 74. Upon further investigation I found that a PO has already put a crank and rods from a 258 in it. Already stroked haha. I decided shift the focus of my upgrade budget to the flow (Intake/exhaust). Currently have original exhaust manifold (starting to crack) and the original cast iron 1 barrel intake with a Carter carb.

Re: AMC 232 upgrade routes

Posted: August 21st, 2022, 11:20 pm
by Cheromaniac
You're missing one important ingredient to build a stroker, and that's the 4.0L block with its bigger 3.875" cylinder bore. While the 258 is indeed a stroked version of the 232, it still only made a measly 110hp because it had poor cylinder head flow and breathed in/out through a tiny straw.
You could increase that number to 170-180hp with more torque across the whole rpm range by performing the following upgrades:

1. '91-'99 4.0 cylinder head (either 7120 or 0630 casting). This will also increase the compression ratio from 8.0 to 8.7:1.

2. '99+ 4.0 curved runner intake manifold with injector bosses welded up plus an adapter plate for a Holley 390cfm 4-barrel carb.

3. '91-'99 4.0 eBay header plus 2.5" exhaust.

If you also upgrade the camshaft and add 1.6 ratio roller rockers, 200+hp is possible.