I've been doing some reading on various websites (including the HAMB of course) and a great deal in Tex Smith's book on Hemis lately. During all this reading I still didn't quite seem to find what I was looking for about early 331's. They don't seem to be as popular because of the extended bell housing (obviously), but I haven't found a real good reason beyond that. So here's my specific questions that maybe someone can shed some light on for me: 1) Can any other heads be used on the 51'-53' 331 (I.E. later 331, 354 or 392)? 2) How about cranks? What can I use? 301, 331, 354, 392? 3) How about intake manifolds? Will it be the same as the other models? I know there were some significant changes made in 1954 and more in 1955 so... 4) Can heads be exchanged between 1954 and 1955 331's? I know there are plenty of rebuild and performance parts available for the 1951 to 1953 331's; pistons, cams, valves, tranny adapters, etc., sooo... 5) what are the reasons (if any) NOT to build up an early 331 Hemi for a good running street motor? Trying to keep all my options open to early Hemi motors, but I don't want to get myself stuck with something not worth building either. Thanks everyone! Sorry so long!
1, All heads except the 392's can be used on the 331 2, All except the 392. 3, All manifolds will work with the same style heads. IE early mani on early heads etc. This due to the water outlet. They all will fit and bolt up. 4, Yes 5, Hard to put auto. trans behind them. Adapters are few. Take up more floor room.
301,331, & 354 cranks are the same. The easyesthead change is '54 heads, bigger ports & valves. The 54 intake is a 4V instead of 2V. There is a change in locting pins on the 55 heads. Spacing is critical because of the tiny passage that sends oil to the rocker assemblys. You could use 55 heads & intake if custom pins were used, they would need to be persisely made. You would need to use 54 heads & intake or 55 heads & intake.The main problem has been few choices of tranny adaptors, that seems to be changing, and the small ports & valves on the 51-53 heads. Standard rebuild parts for the 51-53 are the most expensive of the Chr. Hemis. 392 is the cheapest parts
Scooter - I'm going thru pretty much the same deal, except that the base motor is a 301 poly from 1955. There appears to be much conflicting info out there, but here's what I've been able to find: a) Blocks - the only difference I've been able to find on the pre' 55 blocks is the bellhousing. everything else is the same, as far as I've been able to see. The only real difference seems to occur in '56 and up cam drive systems; they were simplified and most of the current accessories available are for the late cam drive systems. You'll see reference to short vs long snout cams - the shortie snouts are the later cam. b) Heads - Pretty much every chrysler hemi/poly head will bolt up to every chrysler hemi/poly block. There are two port configs available on the hemi, and the '55 heads (known as tri-fives for the first three casting numerals) supposedly flow the best. 392 heads are oddballs, as they have a different intake flange height to compensate for the raised deck. If you were to put 392 heads on yer 331 - the intake would not fit. As far as the 54-55 swappie - yeah. It will work fine. c) Intakes - the difference between early and late intakes is the location of the water outlet. early intakes have the water outlet cast into the intake; later manifolds have the outlet separate. When you're updating the cam drive system, you can go to a BB chevy waterpump and then mount up a water crossover/t-stat housing to the ports on the front of the head. As far as not using an early 331... I think the reason folks have shied away from them (in the past) has to do with some of the items discussed above. To build up the motor with something other than a stock induction, you've got to make changes to the cooling plumbing - and possibly the cam drive, depending on which water pump you use. Most hot rodders go for the biggest engine they can get their hands on - and until recently, the 'modern' 331/354/392's were still relatively plentiful. Prices are getting silly on these now - I've seen junk cars with stuck short 331's go for over two grand! That being said the 'long' 331 is a good motor, and is well worth spending the jing on to hot it up. I'm going the other way, personally - next motor will be a warmed-up 354 poly. Same comments apply; just one rocker shaft shy!
HOLY CRAP!!! I LOVE this place! I honestly wasn't sure what kind of response I was going to get! This is GREAT information! Thanks a ton, and if there is anything else, please post it! Thanks and CHEERS!! (chug beer now) Scooter
Few more questions I thought of... 1) Will the rocker assemblies from a 331 interchange with a 354 or 392? 2) If 354 heads are used on a 51-53 331 block, will there need to be any modifications or provisions besides the water crossover added? 3) If the stock 331 heads are used, am I going to have a hard time finding intake manifolds that will accomidate a 3x2, 4x2, or 6x2 carb setup? Thanks again for the previous answers! Very helpful!
Just a quick additional note. I talked to someone from Hot Hemi Heads and he had a couple tips. He said the 354 heads on the early 331 will seep, so he recommended using a later model 331 head (54' or 55'). Then for intake manifolds, drill and tap for a remote thermostat housing to open the market and manifold options up. Sounds good! So I guess that answers my questions also with the exception of... can the rocker assemblies be transfered from head model to head model in the FirePower series?
1954 heads used the same water crossover as the 51-53 , it was cast into the intake manifold with no passage at the ends of the heads . 392 heads can be used but the intake has to be of the U-Fab type or port injectors as the spread of the ports won't let the factory intake to fit . Early 331 cranks, although the same dimensions as the later 331-354 , have smaller oil passages . They are OK for street use . We ran a 404 incher in a Willys coupe back in the early 60s , welded stroker , .125 overbore and long bell . Another drawback of the 51-53 blocks was the heavy assed cast iron front cover and lower bell housing . I built a tin cover for the front using a 55 cover and a cutout 3/16" plate to bolt onto the 331 ,then trimmed the flange off the 55 cover and brazed the two together . We later stuck the same engine in a '27 T altered and ran 126 on cheap gas at the old St. George strip , 1965 as I remember.
Snap too, are you in Vegas? If so, who does good machining work on Hemi blocks in this town (bake, line bore, re-plug, etc.)? Thanks for the additional note on the crank. Good to know. Is what I was told above false about the 354 heads and water jacket seepage? The more I'm thinking about it, it doesn't fully make sense, but I'm not the expert here either? If I recall, I think Jimmy White told me he's not running 331 heads on his coupe. 354 or 392 heads. 354 Jimmy? Is anyone running 354 heads on a 331 here? What's the verdict?
If you talked to Bob Walker himself @ Hot Heads & he said there is a problem, there probably is, though I haven't heard this one before. Many aftermarket intakes are drilled foe fittings to use hose to the remote thermostat,if not it's easy to drill out & tap the holes using the gasket as a template. As I mentioned earlier there is a change in locating pin size on the 55 heads. The 54 are bolt on.
Not sure if it was Bob or not. He mentioned his name, but he said it so quick I didn't catch it. May not have been. George, you mentioned the intakes changed from 2V to 4V... so it seems that the rocker assemblies wouldn't transfer from the early 331 to the 54' and up. Would the assemblies interchange between the later 331's and the 354's and 392's?
As far as I know all of the Chr. interchange. There have been comments about the strenth on the ones on Ind. engines. I think you would be best off getting a new 354 cam from Bob. With a "ring" spacer you can use a 318/340 timing chain. It's cheaper than regrinding it, desnouting, & then having to use adjustible push rods. Use pre 67 413-440 lifters.
Now you're talking outside my knowledge bowl (or cup)! When it comes to interchangability between other Mopar motors and models, I'm totally clueless. Only been lookin' at the Chrysler stuff so far. Lot more to learn I guess!! At least I know I can do something with an early 331 now! Just need to convince my better half "it's a great idea to have another car related item sitting around" so I can look for one!
Jimmy's running 354 Industrial heads on his early extended bell 331 (bored .125). I can vouch for the fact that it runs like a raped ape. '55 331 heads are supposedly the best casting as far as port flow, and the stock valve sizes are adequate for a good street strip motor. '54 heads run a close second I believe....but most people want the '55 heads because of their water outlets on the heads. '54 heads don't have water outlets on the heads...they use the outlets on the intake. '51-53 heads are not as desirable because of their small ports and (I think) smaller valves.
Thanks for that bit of info Bass! I didn't realize that was an extended bell motor also. That's good to know! BTW Bass, your Hemi coupe build is lookin' GREAT! Been following closely. I love that 4x2 intake you're running on that Hemi too!! Very nice!!
I'm not aware of any difference in rocker shaft assemblies. No other mods required that I know of; although there are differences in the intake manifold crossover flange dimensions. The later heads have a higher roof on the crossover port, and the earlier heads have a lower port. I had to modify my poly heads slightly to accept a later intake manifold - but other than that the setup worked fine. As for intakes... The nicest intake I've seen (other than the home made ones) is Bob Walker's tunnel ram (Hot Heads). It's nice because the base design flows well, and it's been designed to accept an adapter plate which shares the same base dimension as a 6-71 blower. You can run either a blower, a single 4bbl, 3-2bbls, or 2-4bbs on the base tunnel ram. It's a neat setup - has about 7-1/2" of rise if I recall right. Other than that - Weiand still makes a low rise 2x4 that bolts up to the 331-392 chryslers. Didn't like that one as much as the 'shot' into the intake bowls isn't as straight as on the tunnel ram - kinda defeats the purpose of a multi-carb setup. Build that motor, boy!
Anyone have good suggestions for Hemi rebuild books or videos and where to buy them? I just have Tex Smith's book and a whole bunch of catalogs right now. Was thinking the factory repair manual for that year might be good. If I use later heads should I buy the later year repair manual also? Only rebuilt SBC's, so this is a whole new ball game for me!
Scooter , Universal Machine at 212 W Utah is the best Machine shop in LV by a mile. 384- 5858. Steve has been doing my work for close to 30 years , never a miss yet. Most of his Machinists have been there for years, his crank grinder at least 25 for instance. Dave
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