383 e.t. Goal

[The Green Coronet]

Im new here so sorry if this is in the wrong section. Anyways I just bought a 1968 coronet 440, it was a 318 but the guy had a 383 for no charge so why not. I am wondering what would have to be done to the 383 to get into the mid to low 13 sec range. I have 1 from a 1968 newyorker probaly the low perf model and one from a 1970 challenger (mabey). The coronet has a tf727 and will be built to rt specs MINUS THE 440. I don't know what my weight will be when im done but the car will be stock minus soundproofing.

 

[GTX MATT]

I would say without headwork 9:1 compression and 230-240 degrees of duration @ .050 with 2500-3000 stall, headers (summit cheap 1 3/4 are good, same as Hedmans), good exhaust, good tune up, 3.91s+. Single plane intake or an Eddy RPM, 750 cfm carb. Make sure the engines in decent shape to start.

The 474 purpleshaft or the Comp Nostalgia 474 (comp's version) is a good place to start if you're running stock pistons. It may hit 12s if you sort it out real well.

 

[Meep-Meep]

X2 ^^^

I was running mid 13's on street tires in a 68 383 B body. 700 DP Holley, Torker, Isky 280 / .465" cam on a 108 LSA, Mallory dual point, pocket ported 915 heads, headers, 3.55's and a 4 spd. You want the 108 or 110 LSA cam to put the power peak up high so you can spin it to 6000 RPM easily. Basically the same engine went 12.65 with a MP .528" cam, a bit more compression and a lot more gear (with slicks).

 

[Garys1969RR]

You can see what others are using if you look at the 13 second combos that have been posted. If you can go to the longer stroke version of the big block(3.75"), you will have more power and torque with the same cam/head choice. You can even use your 383 block, put in a 440 crankshaft and come up with a 426!

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Go to the racers hangout on this forum, and you can see what guys are using in their 12 sec combos.

 

[The Green Coronet]

You can see what others are using if you look at the 13 second combos that have been posted. If you can go to the longer stroke version of the big block(3.75"), you will have more power and torque with the same cam/head choice. You can even use your 383 block, put in a 440 crankshaft and come up with a 426!

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Go to the racers hangout on this forum, and you can see what guys are using in their 12 sec combos.

The problem I found with the racers hangout was there was not many 383 builds. But one day I plan on doing a 440 stroked to 500, but right now I'm young and poor. I have been contemplating wether or not to even build this engine if I wanna go to a 440 in a few years anyways.

 

[furyus]

Keep in mind, the big block and small block have a different bell housing bolt pattern, so you will need a big block trans for the 383.

 

[GTX MATT]

And drive it with the 318? Don't do it, I wish I had shoved a big block in my car earlier, I got the car when I was 17 (having owned a GTX for a short time before that) and drove it with the 273 for about a year and a half. I wished I put the big block in day 1. The stroker will snowball into a 7K project, throw the 383 together for 500 bucks now and lay some rubber.

Don't fall into the "Do it once do it right" trap that many online will set for you. Are they right? Sure for the most part, but lots of these guys have cars that haven't been on the road in 10 years and aren't having any fun with them.

 

[Garys1969RR]

The problem I found with the racers hangout was there was not many 383 builds. But one day I plan on doing a 440 stroked to 500, but right now I'm young and poor. I have been contemplating wether or not to even build this engine if I wanna go to a 440 in a few years anyways.

It costs about the same to build a 440 as a 383. Think carefully before you do this. Build your engine on the computer before doing the real life build. Will save you a bunch of headaches. Plus by then you should know exactly what your doing and what to expect.

 

[The Green Coronet]

Keep in mind, the big block and small block have a different bell housing bolt pattern, so you will need a big block trans for the 383.

The engine and trans came as a package and i think the same guy has a spare rear end. And I have no plans for putting the 318 in the car, thats for the snowmobile.

 

[texas69bee]

Figure out exactly what the car will be used for and stick with YOUR plan. If your into big and loud then go with the 440. Speed is not all theses cars are good for. Sure its nice to have something badass, but if you want to talk to your wife while out cruising or you don't want to have to keep giving it gas at the stop light because the vacuum sucks cause you went with to big of a cam, then go with the 383. I chose the 383 route.

 

[Garys1969RR]

It costs about the same to build a 440 as a 383. Think carefully before you do this. Build your engine on the computer before doing the real life build. Will save you a bunch of headaches. Plus by then you should know exactly what your doing and what to expect.

Start with desired engine power band desired, from that you can choose the cam, intake manifold, and carb. Fuel you want to use will help to determine compression ratio desired. Go to the KB Piston website for C/R calculator, plug in the specs such as deck height, chamber volume, piston flat or dome, gasket thickness, etc. Then you can juggle different sizes/specs till you get to where you want to be.

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Oh yea, cylinder head choice is extremely important. Get a good flowing head, match the ports, and use one with a runner size compatible with your build. Generally, smaller ports (such as factory heads have) will tend to make better low end torque, but won't breathe as well at higher RPMs. Larger well designed ports should allow the engine to breathe better at higher RPMs. But the low end torque may suffer. These are guidelines, and there are so many variables involved, that nothing is set in stone. Good luck.

 

[The Green Coronet]

Thanks for the help guys. Ill have to see what budget allows when the time comes.
What do you guys find more fun, low rpm torque or high rpm power?

 

[Dragondan64]

Yeah my advice from experiences with both 383 and 440's the 440 is the much better route for tires shredding torque! Doesn't take much to run mid 12's through the mufflers on good tires such as M & H racemaster street tires. Good valve job on some 906 heads with purple shaft cam around 484 lift or the 509 lift hydraulic cams and matching valve springs, maybe a 2500 converter with 3.91 gears and you should keep the compression ratio under 10-1soits pump gas friendly, good electronic ignition, wires, good edlebrock rpm intake or mopar perf intake single plain or dual and a carb good for your altitude. I live I Colorado from spring to fall and then florida from fall to spring and have carbs for both altitudes.

 

[clintmopar]

What computer program do you recommend to do a engine build with?

clintmopar

 

[dvw]

Stock short block, [email protected] cam, correct valve springs, headers, eddy performer rpm,your choice of 4 barrel carb, 4.10 gear. This will get you there easy if the short block is not a total turd. Look for used stuff, it's everywhere.
Doug