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4.0 head on a 71 232

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71amchornet View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote 71amchornet Quote  Post ReplyReply Direct Link To This Post Topic: 4.0 head on a 71 232
    Posted: May/04/2018 at 9:21am
Does anyone know if a 4.0 head will fit on a 71 232? I'm looking for any ways to slightly modify my 232 without swapping it out, I already have a swap I want to do but I want to do a little to my 232 possibly.
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ramblin64sw View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote ramblin64sw Quote  Post ReplyReply Direct Link To This Post Posted: May/05/2018 at 11:38am
Yes, it will fit, but it will require you to plug some of the water jacket casting holes in the cylinder head. There are a number of posts on this subject if you do a search here. I have a 4.0 head on my 64 232, and am quite pleased with how it turned out.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote GreggR Quote  Post ReplyReply Direct Link To This Post Posted: May/15/2018 at 10:40pm
Some questions...

Did you do anything to the 4.0 head... shave it? valve job? Valve springs?

Did you add an aftermarket cam?

Carb or EFI...?

Thanks in advance...
Skating away on the thin ice of a new day.'75 Hornet Hatchback
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Post Options Post Options   Thanks (0) Thanks(0)   Quote vinny Quote  Post ReplyReply Direct Link To This Post Posted: May/16/2018 at 10:10am
I've not done the head swap yet to a spare 66 engine but considering it. A cam I think is needed because the stock one is pretty mild.

From what I am reading here there could be a difference in deck height between different vintage 232's so pushrod length would be a factor and some 232's have solid pushrods so they would need replacing. 

Someone was exploring the possibility of using Ford 2.3 L pistons which are .030" more than our std pistons and higher compression but have different pin dia's. I wonder if anything ever happened with that?  


Edited by vinny - May/16/2018 at 7:26pm
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Post Options Post Options   Thanks (0) Thanks(0)   Quote ramblin64sw Quote  Post ReplyReply Direct Link To This Post Posted: May/17/2018 at 12:01am
I used 0.100" long sbc valves and springs. The valves are 0 .060" longer than the stock 4.0 valves. I had the spring seats on the head cut to accept the sbc springs. I put 0.060" shims under the rocker pedestals and used a 9.5" pushrod from a Ford 400m. 





Edited by ramblin64sw - May/17/2018 at 12:09am
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Post Options Post Options   Thanks (0) Thanks(0)   Quote farna Quote  Post ReplyReply Direct Link To This Post Posted: May/26/2018 at 11:11am
If you use the stock 4.0L head and valves you just need the Ford 400M pushrods. While the 4.0L head is MUCH better than any 199/232/258 head, you won't get much gain from just the head swap -- maybe 5-7 hp, which you would hardly notice. The big gain is in swapping a better cam along with the head, and a better carb and intake... or the EFI system. You have to use the 4.0L header, and can use a 1980-89 258 carb intake. You want to ditch the feedback BBD carb. An earlier non-feedback BBD will work, but something like a 1.08 Motorcraft 2100 (287 cfm) is a much better choice. The head/cam/intake/carb combo really wakes a 232/258 up. I'd use something like an Isky 256 or 262 Supercam, or the Comp 260H.
Frank Swygert
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Pdok Quote  Post ReplyReply Direct Link To This Post Posted: May/26/2018 at 1:18pm
Agreed w/ Frank.  I would add a switch to HEI or some variation thereof as a must-have.

Not to discourage the head swap idea, but depending on your goals here, you can really get some major benefit from the cam/carb swap.  Just keep the stock head, if it's in good shape, then you can bolt your stuff back on.  if you don't like the stock intake/exhaust, it's pretty easy to find the intake/exhaust combo you like, just like Frank says.

Remember you can also have the stock head shaved quite a bit and boost compression.  If you're already taking it off and having it surfaced or rebuilt, consider running some compression calc numbers on shaving it down 040 or 060 at the same time.  I'd do that for sure if you swap the head either way, and shoot for in the 8.9-9.2 comp ratio range.  Don't know what your motor currently is, though.

I've done this both ways on the same bottom end.  Did a stock head but a sweet cam upgrade with several combinations of carb and intake, on a header exhaust.  Then, head swap (shaved 040) on that same cam w/MPFI and Clifford header.  I can definitely tell the difference after the head swap, but the MPFI pays off with a very reliable and zero-tuning required delivery system.  That said, it was still a different motor with the stock head and the cam upgrade, and I'd say 80-90% as strong as the motor with the 4.0 head on it.

The motorcraft 2100 variety carbs were the best, easiest to tune. That is to say, it took all of 5 minutes to set choke, mixture, idle.  Loved it.

There's some argument for a split-pattern cam, but for your scenario not much benefit I think. Whatever you choose, you'd be far better off with cam numbers that allow you to keep stock valvetrain components, unless you're really wanting something lumpy.

I think the more lift you have for the cam, the more that head swap helps with airflow at elevated RPM. So, if you stay in the mid-.400s on lift, the head swap is a relatively small addition to the whole package.  Just an opinion, not backed up by dyno-testing or anything.

Don't forget you need to be able to provide a reliable spark!  The MPFI timing control is an outstanding benefit of going that route.

Also, just to muddy the water, there are many carb-style TBI systems out there now that wouldn't require a head swap to get reliable performance on air/fuel delivery and eliminate carb tuning issues w/the cam upgrades.  If I had it to do over, I probably would have tried that too.

76 Grem X 258/904,4.0 head/MPFI, Comp X250H cam, Hughes springs, Clifford header, serpentine swap.
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Post Options Post Options   Thanks (1) Thanks(1)   Quote farna Quote  Post ReplyReply Direct Link To This Post Posted: May/28/2018 at 8:32am
I generally only advise the 4.0L head swap:

1) You're building a performance six. No need to explain why here! The 96-99 head is probably the best flowing AMC six head ever made, end of story.

2) You really want a header/better exhaust manifold. The stock 4.0L exhaust manifold is essentially a header. Headers for the older engines cost as much or more than the 4.0L head conversion, and aftermarket 4.0L headers cost a good bit and aren't much (if any) better than the stock header. Even the log type 87-90 Renix exhaust manifold flows well, much better than the cast iron 232/258 manifolds. The 200-06 models use a split cast iron exhaust manifold (two three cylinder manifolds). While smaller in inside diameter, they flow well when matched to the 2000-2006 head. That head was tuned to produce the best power below 4000 rpm, so it's great for a cruiser. The earlier head and exhaust is better for a drag engine, but that's about it.

3) If your head already needs rebuilding it doesn't cost much more to get a 4.0L head/valve cover/exhaust manifold from a local pick-n-pull yard (if there is a local one). Assuming you get a good head that only needs valve stem seals (I'd replace them anyway since the head's off) you're not out much and have a much better exhaust manifold and valve cover. Especially good if you have an 80s 258 with plastic VC!
Frank Swygert
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