I'm building a 383 for my GTS car and looking for low 12's or high 11's with stock 906 heads and pump gas ? Any combo's you guys currently running in an Abody ?

i can tell you what didn't work for me in a 67 b-body.

i had a 383, stock stroke, KB pistons, stock rods, decked block, shaved 906 heads w/~ 9.2:1 compression, stock rockers, magnum double springs, large valves, 284/484 purple shaft cam w/hydraulic lifters, M1 single plane intake, 750 cfm edelbrock carb, hedman headers, 727 w/ 2500 (rated 3000) stall torque converter, 3:55 rear gears, stock suspension. it was a dog. i couldn't do a burnout in first gear because the power band was 2500-5000 rpm and i couldn't foot brake it - it just rolled forward before it got to 2500 rpm. it could pass on the freeway and do burnouts from first to second though. i think it was improperly tuned and i should have bought a higher stall torque converter to utilize the power band on the engine. some suspension upgrades would have helped as well.

If you're on a budget, there's only one piston choice that makes sense to me: the KB400 Hyper. It allows you to get compression. I think if you can shave your 906's down to about 86cc's, you should be able to get near 10:1. (I haven't figured this one in a while) A template porting job with a back-cut on the exhaust valve would sure help you out. It will be a high RPM motor, so don't cut corners on the bottom end! balanced with new rods & drilled for a 1/2" oil pickup are things I'd do. If we're talking hydraulic cams, I would consider the comp XE285HL or the Lunati VooDoo 513/533. To keep a cam that size livable on the street, you may want to look at some Rhodes lifters, they have new adjustable ones out that look interesting. I installed a set of original rhodes in my 383, and I liked what they did for my motor. I like the Eddy RPM manifold, but a good single plane might be a good choice as well. A well prepped Holley 750 should be about right. I'd choose 1-7/8" headers. That setup will want about a 3500 stall if you're running an Automatic, and going fast with a 383 means gears! 3.91's minimum.

I think thats a decent build that should be well into the 12's if properly tuned.

My son runs a stock stroke 400 which is just basically a bored 383. If you read this post you can read my post about his street car combo in his Dart. I even posted a pic of his Dart racing me. But he has run 11.40's @ 117 and he had it out driving it tonight. Ron

https://board.moparts.org/ubbthreads/show...rue#Post4601088

ron =

Thanks guys anymore ?

.040 over, 10:1 pistons, have you heads cleaned up and if can get 2.14/1.81 valves port them as much as you can. 528 or 557 solid w/ 1.5 roller rockers, (don't use the 484 or 509) 1 3/4 headers, RPM intake (you will need a drop base or cut your hood) 1/2" 4 hole spacer, holley 850DP (stay away form the carter/eddy carbs), 3400 stall and the rest of the usual bolt ons. That with 3.91's or better should get you pretty close to 11's (it def would if it was a 440)

I can tell you what was in my 63 fury, 383, MP11-1/2 to 1 pistons, windage tray, 906 heads mild port, 509 purple cam, holley street dominator manifold, holley 750 , electronic conversion ,hemi converter, 4-88 shure grip .this ran on a mixture of pump and trick at local track at 12.32s(only made a few pases). I did change to a 590 solid and a holley 950 dp but never ran it. good luck BOB

Well sounds like for sure 3.91 gears , 3500 stall converter , Eddy RPM manifold and decent size headers seem to be the common thread . Holley for sure 750 to 850 range double pumper. Cam and heads are still up for grabs. Also sounds like the bottom end will need be strong living mostly in the upper rpm range to keep the 383 happy. You guys rock

achieve .035-.040 QUENCH(piston to head clearance) which is a PITA to do on open chambers such as your 906's but very desireable. any chance you could scare up a set of 915's(for the closed chambers)?

http://www.youtube.com/watch?v=I8XTNpxaa...p?v=I8XTNpxaats

I beleive he runs 12.30s in that B body with that combo. I think you could run the KB pistons for 10:1 (Althought Id rather see a forged piston as that mill should see some revs hard, depends on the owner though. Id like to open the car up often so I would definately go forged), run the .557 purpleshaft, maybe clean the heads up, RPM intake, 1-7/8 inch headers, 800 DP, 4.10s, 27-28 inch ish tires, 3500 stall and Id think it might run 11.90s-12.00s. You might have to play with the intakes and try a single plane for best times but if you want to do that start with an RPM then try a single plane because if the single plane works better you wont have any trouble getting rid of the RPM.

What years were the 915's used I just picked up a 1966 383 for the build but still have the original 1969 heads and crank in the 400 in the car. I think the guy blew up the block on the original one .

I also like to romp the pedal a little so forged may be the right choice.

915s are a 1967 only head and will only be found on the 440.

The 350 hp 440 will have the 1.60 inch exhaust valve while the 375 hp 440HP heads will have the 1.74, it doesnt matter as you can change the exhaust. The 516 and earlier closed chambered heads arent desirable because of their poorly designed ports.

You can get on it with the Hyperblahblahblah (man I hate spelling that word) or cast pistons, but when I get on it I take the car all the way through the powerband. I think the general rule of thumb is cast is safe to 6000ish and Hypers to 6500. You can rev them up more than that without trouble but I would be doing it ALOT so Id go forged since the thing is probably going to pull hard to at least 6500 with the headers open if you go with the .557, youll be on the line Id say.

I know someone who runs the .509 in his 440 Dart and when he runs the headers open he gets his best times shifting around 6500 if i remember right, and the .557 is bigger than the .509 duration wise and the 383 is smaller, so it might even want to get up to around 6800 or so with the headers open and a single plane intake.

Probably not going to find any 915's around here anyways (Alaska). The car will hit the track maybe 4 to 5 times a year and street light romps often so forged sounds like the proper choice for me.

Okay KB Hypers sound tough enough eight years and many passes sounds good.

Thats one thing i've kick around (using the 400). I won't know its condition until I remove it today or tommorow. I was kinda wanting to say it has a 383 in it just for that originality thing but