Heads: 401 vs. 304

CJ-7-401

Can you put AMC 304-V8 heads on an AMC 401-V8?? I realize the 304 heads have smaller valves. The reason I ask... I have a "401" as identified by the cast "401" on both sides of the block. I also have a metal tag on the passenger valve cover that identifies the engine code as "H" which is a 304. I also have 2 bbl manifold and carb (MC2100). I'm thinking that that 304 blew up and the PO found a short block "401" and put all of the 304 top end (Heads, valve covers, manifolds, carb, ignition, etc) on top of the "401" ??? Does that sound logical? is that possible??

73hornut

More likely that the valve covers and intake may have come off of a 304. Whats the casting # on the heads?(under valve cover)

CJ-7-401

73hornut wrote
More likely that the valve covers and intake may have come off of a 304. Whats the casting # on the heads?(under valve cover)

I agree w/ you on that. I'll take off the valve cover and see what is cast into the head.

CJ-7-401

OK, I took off the drivers side valve cover. It had the following markings: Between the 1st and 2nd cyl in this head, there was a HN and a "77" diagonially above it. Between the 3rd and 4th cyl, there was a casting # 3231480-2 and a backwards "C" below it. Does that tell us anything???

tufcj

The 3231480 casting number doesn't show up on the charts I have. What color is the block? Being a 2bbl, if the block is red, it could have been a 401 from an IH Scout. My bet is that the valve cover was changed somewhere, and the rest of the engine is OK. Bob tufcj

CJ-7-401

tufcj wrote
The 3231480 casting number doesn't show up on the charts I have. What color is the block? Being a 2bbl, if the block is red, it could have been a 401 from an IH Scout. My bet is that the valve cover was changed somewhere, and the rest of the engine is OK.

Bob
tufcj

The block is red. but it was repainted. But could of been red originally and repainted the original red color.

I know some of the late 1974 IHC Travelalls were made with AMC 401's w/ 2bbls because IHC ran out of their 392-V8's (strike at the engine plant) and bought some 401's from AMC to finish that model year.

jeepsr4ever

You can get a red 401 from a California jeep or AMC car or a Travelall from 1974-1976 and they always had the good 4 planetary 2wd 727 tranny ebhind them. In 1974-1975 they used a dipstick that folded over the drivers side valve cover (NICE!) and then went back to std AMC tubes in 76.

CJ-7-401

My dipstick is the normal one. Back to the head casting number. On the "sticky" that references Head Casting numbers: the 323 prefix seems to be for heads on AMC engines in the late 70's. The chart doesn't go that far on the 401's. We know Jeep (FSJs) had 401s from 1977 - 1979 where can I find the casting #s for the heads for these engines during those late years???

Dusty

:t: FSJ's with 401s came in 74-78 with a few early 79 FSJ motors (very few though in 79)

Wrench Man

IH didn't put 401's in Scouts, they were in Travelalls and supposedly pickups, but I've never seen one. The "480" castings are late 70's early 80's 360/401 castings, I'd say his were made in '77?