Hey Jeep Fans.

A buddy of mine has an IH Scout 800. He wants to put the AMC 258 motor in it.

I want some clues as to how I can identify the AMC 258 from the AMC 232 (stock motor in the Scout).

I understand that there are some stampings and some other minor features but I need some hard facts, not wishy washy hear say.

Tell me what you know and help my buddy out.

Thanks. <img src="/forums/images/graemlins/notooth.gif" alt="" />

Does this help?
232

The 232 cubic inch/3.8L (231.9cuin / 3,801cc) 232 was produced from 1964-1979. Through 1970, the engine shared a deck height with the 199. Starting in 1971, AMC raised the deck height to produce the 258, and the 232 adopted the 199's longer connecting rods. Bore and stroke remained the same.

Applications:

Rambler Classic (1964-1966)
Rambler American/AMC Rambler (1964-1969)
Rambler/AMC Marlin (1965-1967)
Rambler/AMC Ambassador (1965-1970)
Rambler/AMC Rebel (1967-70)
AMC Javelin (1968-74)
AMC Hornet (1970-77)
AMC Gremlin (1970-78)
AMC Matador (1971-74)
AMC Pacer (1975-79)
AMC Concord (1978-79)
AMC Spirit (1979)
Jeep CJ (1972-79)
Jeep Cherokee (1974-79)
Jeep Wagoneer (1965-1971)
Jeep J series trucks (1965-1970)
Jeep Commando (1972-1973)
International Harvester Scout (1969-1971)

Big JIm <img src="/forums/images/graemlins/pfft.gif" alt="" />

For a number of years there was a number on the side of the block that indicated the size.

I know it was there for the AMC 304-390-401 series.

Other than that, the VIN does contain an engine ID code.

The 258 and 232 have a common block casting number. They are machined exactly the same way, year for year. There is a number stamped on a boss near the distributor that gives the engine size, A or E is the difference. Over the years, the parts could have been swapped around during a rebuild. The only way to be sure it's a 258 is to measure the stroke. A 258 has a 3.88" (3-7/8") stroke, a 232 has a 3.5" (3-1/2") stroke.

If your buddies Scout 's 232 block and head are good, simply install a 258 crank and rods and you will have a 258!
The '72-'80 crank is fully counterweighted and is smoother running than the lighter '81-'90 crank. The later crank has a shorter front snout but will still work with the early pullys/damper. The '70-'71 258 crank is only useable with a stick or Borg Warner automatic, but is fully counterweighted, too.

Personally, I would consider installing a later 4.0l or 4.6l stroker combo (.030" over 4.0l block and head with a 258 crank) with '91-'95 Mopar EFI. The driveability improvement, power output and torque will make a world of difference over the old 232 and probably give better fuel economy, too. CJOffroad.com has an excellent 4.0l swapping forum with all the help you would need to adapt the EFI from a Cherokee, Grand Cherokee or Wrangler to your earlier vehicle.

Hope this helps!