Hey, a few questions...
1. I am putting a 383 stroker in my 76, and one of my buddies told me it was "ABSOLUTELY NECESSARY!" to get a stall converter to replace my stock torque converter. What is the valididty of that? Would putting a stall converter in make it idle lower?
2. When i pull out my old engine im taking the tranny out with it. Do I HAVE to drop the cross member to get it out? I would really rather not mess with my pipes, but if I have to.... And when i take out the tranny how hard is it to replace the front and rear seals?
3. I know nothing about the specifics of carburetors, but will running my stock quadrajet on that 383 cause problems?

I think thats it. I appreciate the feedback.
-Karl

 

:seeya If you want to match the capabilities of your new engine (and its power curve) you would most LIKELY need a higher stall converter (if its a street car, c. 2500 RPM would be appropriate-this will let you launch in your powerband-anything higher than that, you'll get slippage, heat, and bad things like that). You need to talk to a trans. expert, and they can match your camshaft profile (the most important thing for determining the stall speed of the convertor) and your rear gears to give you an optimal selection. A New convertor will not make it idle lower, it will still be the same. No, you don' t need to fuddle with crossmembers, just the engine/tranny mounts (that's if you take them both out at the same time, otherwise, if you want to drop the tranny and leave the engine in, you'll need to take out the crossmember. Unsure about the seals-seals of what? and third, you'll probably want a different carburator, or at the very least, rejet the old one after cleaning it/rebuilding it. Hope it helps. :cheers:

 

Just to clarify a few points here. You absolutely do *NOT* need a new torque converter. All torque converters have a "stall", so a "stall converter" is a misused term. The common meaning of the term "stall" is really the "flash stall" of the converter, which (very basically) means that behind a given engine it will start transferring power to the transmission at the rated RPM when power is applied rapidly.

To get maximum performance, you would want to match the torque converter stall speed to the power band of your engine. Any of the major torque converter vendors can do this for you if you have the specifications of the parts in your engine (cam grind, intake, displacement, etc)...

You can still use your quadrajet, but you will need to get an intake with the correct mounting pattern for it. You'll probably need to tweak the jetting, idle mixture, power valve, and the carb may still be too small, but I don't really know anything about Q-Jets other than they scare me:D. Lars would be the one to ask about getting your carb setup properly, he's the resident Q-Jet expert. You'll need to provide more information about the 383 to guess if a given carb will work with it. Also, the carb specifics would be necessary (casting numbers should be enough unless you know the CFM & current jetting, etc, etc...).

The front and rear seals are easy to replace. The front seal (pump seal) is just behind the torque converter, which just slides right off once you disconnect the transmission from the engine... The rear seal is also very easy to get to. I'd also stick a new filter and pan gasket in while you're at it.

 

The stock converter can work, depends on the setup. For correct converter you need to give the cam & setup.

 

Her are the specs on the 383
4 bolt main block bored out to .080 over. 3750 stroke crank make this engine a 392 cubic inches. It has a set of late 80's style Corvette aluminum heads with all new valves and springs to match the .480 lift hydraulic cam 290 duration, High rise aluminum intake. 5.7 long rods with ARP bolts, new rings , rods and main bearings. Cam brgs freeze plugs , Fel pro gaskets.

 

.080 over??? You sure about that? That's some serious overbore.

Anyhow, for the torque converter, sounds like you have most of the info you'll need to make a decision... Is that aluminum intake a single or dual plane? Also, you need to know what gears and tire sizes you are running... Also, if you plan to drive the thing on the street or track it makes a *HUGE* difference. I went with a 2500 myself as I want to drive on the street primarily and I'm running 3.08 gears... Even still it's a bit high IMHO, but something's gotta give for better performance:D If you call your favorite company up and ask them, they should give you a good recommendation for your use. You should also consider adding a transmission cooler at the same time. Higher stall means more slippage, which means more heat. Heat is the #1 enemy of a transmission.

 

You will probably have to port match the new heads to your headers/manifolds.......also you will find that the new engine will burn more fuel....how much more depends on a number of factors not the least of which is the carb,i doubt that the old carb settings will work and you will need to do some serious tuning.....it is my experince that a qjet can be made to work with a 383,but it was easier to use a holley 750 vac sec...hope it works out for you...john :chevy