what motor to use

[1fastski]

ok heres the deal , i have a 69 charger iam building , i have 2 383 2bbl motors one is a 66 one is a 68 the 68 motor is out of a 69 charger i got for parts it had 45k orig on it but no title and was trashed inside from sitting in a pound since 74 , i also have a 73 440 motor . my question is where did they kill the HP on the 73 440 ? if i use it what do i need to change if enything ? my 69 383 2bbl single exh was 290hp the 73 440 was only 280hp with duel exh and a 4bbl ?

if i keep the 383 to work with what can i do with it in the hp range ? without killing it , compaired to the 440

also what is swapable from the 440 to 383 or 383 to 440 if anything ?

thanks for any info :-)

[rumblefish360]

Heres the deal on Hp ratings from the past.
The pre '73 years were rated at the flywheel. After '72, 1973 and on, the HP rateing was takin from the rear wheels of the car. With the engine installed and all the acc.'s installed.
HP is down due to the load introduced by the Alt. P/S, A/C and the tranny, the driveshaft and rear.
Other things where lower compresion, smaller valves and cam. To also meet emmissions, the engine is saddled with vacuum tubes and EGR valves that introduce exhaust gas back into he engine to be reburned.
The 383 can produce some great upper HP power levels. The 440 has mean torque down low that the 383 can not produce due to its smaller stroke.
If I had a choice, it would be the 440. The 383 can go the distance. But at higher HP levels, the smaller stroke will require higher stall converters and less drivablity than the 440.
Go 440.

[1fastski]

ok thanks , so without all the smog junk that my 69 didnt come with anyhow ,and a nice cam and intake and headers the 73 440 should be the monster it should be ? what heads are junk heads and what are the good ones?

thanks for the info

[6 packin]

The 73 440 is the one to go with. It may or may not have a steel crank, that was the transition year. even a cast crank will be fine with 500 horses in a street applications below 6000 grand. But makes it tough when swapping out converters and flywheels, because of the external balance of cast cranks. Witch is no biggy because you now can buy flexplates from B&M that have the balance made into the flex plate this is a good deal because you can run popular converters and flywheels that are made for steel crank engines that have nuetral balabalance (internal)! Because you dont need to buy wieghts and tack them to your converter, or drill on your flywheel. You need to buy it and balance it with your engine at the machune shop. That way you can swap converters all ya want because name brand converters are balanced well which are nuetral.

[deadhorse66]

You might want to put the heads off of the '68 model 383 on the 440. If they are the originals, they will be 906 castings which flow just a little better than the 346 castings that should be on your 440. The '66 383 should be equipped with closed chambered 516 castings which are about as good as 346s if both are fitted with equal sized valves and ported to match. You will be able to make compression very easily with the 516 versus the other two.

[1fastski]

the 68 383 and tranz i have is orig from the one 69 charger , the 66 383 was out of a truck { iam told} both are 727 tranz . these forums are great , what number do i look for to tell me what heads are what ? will they say 904 ? or what they are somewhere ? thanks again

[b-1ken]

The 906, 346, 452, etc. are the last three numbers of the casting number which you'll find under the valve cover (on top of the intake port - also under the port). I used 346 castings for years with my race 440's and liked them because they were easier to port than the 906's. I found no difference in performance between these two heads. The 452's have a slightly better exhaust port, but I wouldn't go nuts in your case to find them. I'd say, if the engine came with 346's, just fix the guides, check the valves for stem wear (especially the exhaust), have a good valve job on them and go racin'. If you want to go faster, invest in aftermarket heads.

[1fastski]

cool thanks , i just want to build a snotty street car ,i soooooo tired of these little riceburners with there popcorn exhust running around lol .

thanks again for all the great info :-)

[1fastski]

i looked at my heads this morring ,on my 383 one 100% says 906 ,the other i would think is a 906 but looks like it says 908 ? i cleaned it off still looks like 908 .the motor is very clean and shows no signs that it was ever apart .

[1fastski]

ok i got 3 sets of numbers , the first set say 906 { i swear one side looks like 908 } the other heads have me confused . heres the numbers 1966 383= 2780915 and 2406516-7 1972 440 3751213 and 3751213 iam pretty sure the 906 heads are the ones i should use ? does anyone know what the other numbers are?