heads
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From: white mtns
so i think 6m23 is a date but there are no other numbers on the heads at all and a m on the front corner of the head near the valve cover and a circle thats rased with the numbers 1 3 5 7 6 i dont know what order they are in that was the drivers side iam going to pull off the passenger side cover now
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From: Norton, MA
I know the standard 351C/351M/400 2V heads have either an M, a 2, or nothing stamped onto their corner, not sure if any others have M's. That little circle with the numbers is on my M heads too, although I'm not sure what it means, and it could be on every Ford head ever for all I know. 6m23 as a date code means Dec 23, 1976. I think your best bet on finding out what heads you have is to count the valve cover boltholes, that'll conclusively put you in one family. 8 is Cleveland/M. I think 429/460 is 7, 6 is FE, but I'm only positive on 8 for Cleveland, easy look up though.
If you're not doing anything with them, I'm looking for a set of sound rebuildable C/M heads right now and live in MA. You White Mountains as in NH?
AleX
If you're not doing anything with them, I'm looking for a set of sound rebuildable C/M heads right now and live in MA. You White Mountains as in NH?
AleX
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From: white mtns
there is a m on the drivers and a 2 on the passenger head iam going to pull them off today if i have time i will let you all know. can i just pull the intake and use the mirror trick to see the numbers on the head . oh yeah there is 8 bolts to the valve cover
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They sound like stock m heads, but you never know, the only difference that can really tell you wether they are aussies is the chambers, and to check that well...
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From: chicago burbs
6m23 is a date code, Dec 23 of 1976(1977 model year production)
2L9 is Nov 9 of 1972(1973 model year production)
with an M on the drivers and a 2 on the passenger head, they are not a set. the M is a 351M smog head possibly with A.I.R. passages drilled and the 2 head is from a 351C... the exhaust valve bowls are different
2L9 is Nov 9 of 1972(1973 model year production)
with an M on the drivers and a 2 on the passenger head, they are not a set. the M is a 351M smog head possibly with A.I.R. passages drilled and the 2 head is from a 351C... the exhaust valve bowls are different
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From: chicago burbs
no problem running, just that the M head has a restricted exhaust port, that bank will make less power in the mid~upper range
another caution is that the M heads came with valve rotating spring retainers that the 351C's didn't get. the rotators limit the amount of valve lift before the retainers & top of the valve guides make contact and bend pushrods. cam choice is VERY limited unless you change out the retainers & springs. general concensus is that stock 351C heads can handle around .530" lift maybe more, M heads crash around .480"
another caution is that the M heads came with valve rotating spring retainers that the 351C's didn't get. the rotators limit the amount of valve lift before the retainers & top of the valve guides make contact and bend pushrods. cam choice is VERY limited unless you change out the retainers & springs. general concensus is that stock 351C heads can handle around .530" lift maybe more, M heads crash around .480"
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From: white mtns
so i calld the kid i got the motor from, he says that the m head was machined to match the cleveland head is this possible , he also says that it has been bored over 40 with a 400 crank rods and keith black 400 pistons with a zero deck height and 13 ;1 comp i paid 1500 hundred for this motor and now iam getting the smell of bull beep
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From: chicago burbs
i suppose it's possible to match the chamber volumes by milling the deck but the M X port will always suffer, there's a water jacket hidden in there that the 351C 2V heads never had. you'll hit water if you try to 'port' the M head to match
13:1?!
13:1?!
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From: chicago burbs
first thing i'd check when you get the heads off is if you got a 4" stroke crank?
i come up with 10.7:1 for a zero decked, .040" over 400 with 2cc relief flat tops and 76cc chambers
to make 13:1 you'd need to cut about .085" off a 76cc chamber head to make a 59cc chamber
60cc's is in Aussie & aftermarket Closed Chamber territory
i come up with 10.7:1 for a zero decked, .040" over 400 with 2cc relief flat tops and 76cc chambers
to make 13:1 you'd need to cut about .085" off a 76cc chamber head to make a 59cc chamber
60cc's is in Aussie & aftermarket Closed Chamber territory