Inliners International Forums General Discussion AMC/JEEP 258 build-up

I currently own a '69 Javelin with original 232. The head has been milled .060, bronze valve guides, 3-angle valve job,Crane cam: 484 int, 512exh., 216/228 dur. @.050,Offy 4bbl. manifold, Holley 390 4bbl., and Clfford headers. The car runs well, though needs help with original rear gearing.

I have a '73 258 short block which I intended to rebuild and swap on the head, cam, intake and headers so that I can up-grade my trans choices. I would like to make this a screamer and am looking for advice from anyone who has done a similar project.

Should I stay with this cam (only about 2000 miles) or is there a better one? Would a 500 CFM Road Deamon Jr. be a better carb? Would a port & polish of the head produce anything noticable? I read that putting the '69 head on the '73 motor would require a "top-oiler" modification - yes,no? I'm waffeling between a Torque Command with a converter & a shift kit or, a T-5 swap. Any input on the above or other new ideas would be greatly appreciated.

If you look at the starter location on the two motors,you will see they are on opposite sides from each other.If i remember correctly,the change took place in 1972.You will have to change bellhousings to relocate the starter to the other side of the car for 1972 and newer 232 and 258s.I think the bellhousing off of the 1972 and newer 304-360-401 V8 engines fit the six and some of them came with T10 four speeds.Also i have read that 258 engines made for use in Mexico had cylinder heads with bigger valves and large ports in the head.Clifford may be ableto help you in that department.
EvilDr235

I am far from an expert on AMC sixes, but I think the Mexican Hi performance L6 stuff that made it into the US was produced by an AMC-Mexico subsidiary by the name of VAM. Some of it was used on the Levi's "Team Highball" Gremlins and Pacers that ran the IMSA RS series in the early '80s. Serious "Cheater" parts that looked stock but were anything but. Heads, intakes, cams, and probably more. Try Google-ing. Also check some off-road sites as these guys build some pretty hot Jeeps with the 4.0.

I remember the AMC cars at Daytona, they were way fast on the banks, but the Alfas and Datsuns would eat 'em alive on the twisty infield course. I think but am not positive that they used the smallest AMC six available, as the class limit was 2.5 liters, at least for the imports - maybe the I6 was allowed more.

The story i read years ago about the big valve/port heads they were made for high altitude use.I think the story was in Rod and Custom about 30 years ago?
EvilDr235

Javelindan,

I know I'm a little late on this but I run a 258 with the same head, cam, headers, and carb as yours, and it works very well.

Let me know if your still out there.

Chris in KC

Use a 4.0 Cherokee '91 to '93 head - has raised ports & is the best flowing head available.

Really want it to scream ?

Run a 'U' pipe from the Factory exhaust header-
up to near the carb - mount a Turbo onto a weldable flange on the 'U' pipe - then plumb the air to a 'Bonnet' on the carb - check with Blowthru Turbo @yahoogroups.com as to mods for the carbi.

Pump 6 lbs. of boost into that 258 and try & stop grinning.

Strokers@yahoogroups.com put 258 cranks in the bigger bore 4.0 blocks - 4.5 - .

You can also swap over the EFi from a 4.0 along with their very nice Aisin Warner 4spd. automatic trans.

www.mjmturbo.com

contact Jamie as to the correct sized Garret Turbo - should set you back $550.00 .

Be sure to change out the valve keepers & locks to a High Performance brand - as the AMC units drop valves easily.