Thread: Difference between a 354 & a 392 Hemi???

Tweet

....Is there any difference between a 354 & a 392 Hemi in so far as sound, power & performance? {other than 38 cubic inches .... I put a deposit down on one of Big Al's Toy Box's blown 354 Hemi's & then decided to try to get enough money together to just step up to his 392. Al said that's no problem at all as he'll make more money on the 392 but he says that I'll probably be happier with the 354. I asked him why & he said several things; "you won't notice the difference in power, some people even prefer the 354 to the 392" "a 354 sounds better than a 392 because they rev faster" "some people think they put out more power" "they look the same" & so on. Now I know they look the same but I'm not sure if he'd just rather sell me the 354 or what! I have read that the heads on a 354 are superior, is this true??? The motor that this is replacing put out 460 HP & 499 TQ & I'm worried that the 354 Hemi won't even put out that much! Big Al is rather evasive on what power he thinks it'll put out. In fact, he won't even guess! So what HP & TQ do you folks think this motor will put out??? I have a desk top dyno but no hemi on it..... Thanks, Bill

In my advanced years and with all the study that I've put into human beings over the decades, I see a loose thread here. A loose thread is something that keeps eating at you. You're gonna show the car and everybody is gonna say "oh wow, a 392 hemi". You have two options at that point. Just say yeah, knowing that you're tellin' a fib and feeling bad with yourself because of it....or saying no, it's a 354 and having to explain it and then feelin' bad with yourself because you didn't step up and get the '92 in the first place.

I personally wouldn't walk across the street for the difference in the two as far as horsepower, but I would advise you to spring for the '92. You'll feel good with yourself every time you walk out to the garage and look at it. You'll feel good every time you turn the key and fire it and you'll feel good every time someone says "oh wow, a 392 hemi" and you reply "yeah, ain't it a bitch?".

That's my take on it. To me, it's all about eliminating loose threads in life.

The 354 and 392 had about the same horse in stock form, with 392 coming in at about 20 horse more. but the 392 was a far better motor to throw the high H.P and nitro at and drag race. About every drag racer back in the days of gassers, altereds, and nitro funnys and rails used the 392 not the 354. Any hemi would be cool, but tech is right, keep your eye on the prize and get the 392 its a better peice.

From what I've read and some of the old timers have said many felt the bottom end of the 354s were a bit stronger and wound a bit quicker due in large part to lighter rotating assembly and and shorter strike......but there is no replacement for dispacement.

Tech and moon are both on the money about he "feeling" of owning a 392 life's to short to put a car together and sit there and say "I wish I had....." every time you drive it.

Well-----I raced 392s and I have one that I'm building

However---If I didn't have a 92 I would be exstremely happy with a 354

I don't remember all the differencences, but do remember that there was a combination where they used a spacer between the manifold and heads

I build a lot of other engines and I have said for a long time that the crankshaft doesn't know what it says on the valve cover, but that doesn't cut it when it comes to a HEMI (392)

Jerry

The 392s have a 1/2" taller deck height than the low deck 331/354. As the deck height rises, the distance between the heads increases. Most manfactures usually just make a wider manifold to compensate.

Chrysler for some reason made the heads wider which means the low and tall deck intakes interchange. In order to put 331/354 heads such as the low deck 555 heads (usually listed as the the best flowing stock early hemi heads) requires a spacer.

you need a 392?? pm me if you do

.....Thank You Tech, Mooneye, Mike, Jerry & Pat. For the advise & hand holding :-).... Yes I do have a loose thread {LOL!} about having a 392 Hemi! But I also can't stop thinking about how Al said that the 354 SOUNDS better than the 392! So I guess I have TWO apposing threads! One thread about more cubes & one thread about the 354 sounding better! He said that they have the same duration cams {236}so may be the cam just sounds bigger with fewer cubes {although the 392 does have a roller cam, not sure what difference this makes}.... Anyway, Pat I've already commited to buying a motor from Big Al's so it's to late to back out. Jerry also said that he had a complete motor {or could get me one}. I guess I should have posted in the 'Wanted' section here instead of just asking questions & assuming everyone knew what I wanted! Hummm, Mike that's interesting about Chry. making the heads wider on the tall deck 392 so the 354 manifold would fit. Yesterday I went through all of Hot Heads parts on their web site & saw the spacers to run 354 heads on a 392.... "The crankshaft doesn't know what it says on the valve covers!" Good one Jerry! ........
Actually I wouldn't at all mind having a 354, it's just that down the road when I start taking it to the drags {with slicks on it to hook} & I want to go faster the first thing that I'll think of is "if I had a 392 I'd be going faster"!!! Now I can reverse the pulley's for more boost on the 354 & I could then add the Hot Heads aluminum heads. BUT then again, after this I'd STILL be saying; "if I had a 392 I'd be going faster!"....... Anyway, thanks again for all the help! Bill

We ran the 392 back in the old days both as gass and fuel dragster. When using the 354 heads on a 392 you had to use the 1/2 in spacers. Everyone had a set or two in the trailer. They were pretty easy to make too.

We often picked up a 354 just for the heads. Tossed all the rest back in the body and took it to the junk yard. Between all the fuel and gass guys here in the Twin Cities I bet we junked several thousand of these motors some just for a pair of heads, some for just the block. If I remember we even liked the 354 oil pump and a lot of motors were robbed of just the oil pump.

I'm sure Jerry junked more 392's than we did as he ran more than we did. haha Bet you still see split walls in your sleep.