Hello Everyone. Its been awhile since I have posted. Been busy restoring my 73 and just came back recently from the Corvette Convention in New Orleans and had great time. Best was the Food, the Music and many Corvettes. Now back home in Atlanta and working on my 73 Convertible 454. Over the winter, I removed the body and stripped down the chassis and rebuilt it from the ground up. I replaced/refurbished/cleaned everything from, nuts, bolts, bushings, electrical, insulation, fuel and brake lines, steering components and installed an upgraded F41 street and slalom suspension system with single leaf spring. Not a spec of dirt on this car throughout. Now its motor install time. I have the numbers motor454 with 38k miles sitting on the side for future rebuild to 70 specs and will be installing a new 454 street motor I purchased from an estate sale. The wife did not know anything about the motor except it was all Edelbrock components, aluminum pistons and that it was going into a 70 Chevelle. I was able to start it on the stand before I bought it and after I bought it I took it to a Dyno shop for testing/breakin. The numbers came out to 445hp/505 Ft-lbs. I am ready to install the motor this Sat but have a problem deciding what stall converter I need. I spoke with Hughes and had all the information they needed-car weight, tire size, motor size, dyno spec, etc. except for one item, I do not know what size Cam is in there, therefore Hughes could not give me an answer. I have a new Hughes 2000 stall converter but now thinking I should be going with a 2500 stall converter. Can anyone help me out here? I don't want to be burning out at every red light but do want to connect when I need to. I was also considering to start to participate in short and long course competition events. What size converter should I be considering?

 

I just installed a Hughes GM25 2500 rpm stall converter behind a mild 357" with 3.55 gears and you can DEFINITELY tell its got some stall. I haven't really played with it much yet to determine the foot brake stall or flash stall of the unit but.... I know I can roll into the throttle in 1st from a 15 mph roll and it just lights up the tires. The converter is a little loose around town but very manageable. I would think the GM25 behind a 450hp big block would be PLENTY...... You didn't mention which gear ratio you are running but..... I'd venture to guess that your Hughes 2000 stall would likely be enough for you, unless you are going to be running around on sticky tires and running at the track. I don't think you can go wrong with either one but...the 2500 will definitely feel quite a bit looser around town. If you only have 3.08 gears, I'd stick with the 2000 stall.

All that being said, there are better converters out there that yield more stall for the track and tighter driveability around town...but they cost more.

For an out of the box converter the Hughes is decent.


*** EDIT***

For road course work, I'd definitely stick with the 2000 stall... It will be loose enough to let the cam idle in gear but not too sloppy.... You would hate the slippage of the higher stall on a road course. Make sure to install a trans cooler as well. You'll need it.

 

Thanks ajrothm. I have 3:08 gears and for now I will stick with the new Hughes 2000 stall I have already, being that I have installed the Street/Slalom suspension package and I will be participating in some road events. Thanks again for your advice. Sweet looking Corvettes you own. I got a 70 coupe 350/350- auto-matching numbers that just got painted off the frame in the correct color light blue with light blue interior. Going stock with this restoration. First, got to finish this one.

 

I have attempted competition road racing in two auto tranny cars. Back in the 80s I had a SCCA monza spyder. The thinking back then was to use a lower stall. I had a tc shop make a 8 inch 1800 stall with a full manual shift. Even though I had a hot rod. 060 over bored destroked 350 block. Something like 337 ci. The car was kinda a dog even in a 2500 pound car it didn't run well till you got the rpm's up after two years I changed to a non od 5 speed manual and then the car was really fun.

so many years later I have my drag racing vette with a highly efficient 3500 stall 9.5 inch covertor. It was fun to drive on the road racing track. So I read the rules and 427 or less ci got a 300 pound weight break to compete against your typical 496 equipped vintage GT1 vettes. Going to 427 ci with lots more tq increase the stall to about 3800 it put the motor right into the power band

when you buy efficient modern tc they don't hardly slip going down the road. Only at open throttle. You can't beat the fun factor of high stall. Vigilante 9.5 inch