Super Gas Powerglide low gear ratio 1.76 or 1.80

hotrod1446 · 07-21-2009, 06:14 PM

I have a 2700lb Super Street Vega which is powered by a SBC, runs 9.80. Blew the 1.82 planetaries and looking to buy a replacement tranny or gearset. Looking to get opinions on using 1.76 or go for the 1.80. Will use pro brake for the few 9.90 races but will race 10.90 most of the time. Ladder bar with coil spring front suspension. Will the 1.76 get my lame small block off the line quick enough for pro tree racing?

Michael Pliska · 07-21-2009, 07:34 PM

Granted my car was lighter and with a big block, but I found negligible difference with the 1.76 versus the 1.82. Mine is a Super-Gas Vega with a 481" motor, with iron heads the car & driver weighed around 2350. When I first put it together I used a 1.82 for most conditions and had a 1.96 trans (and looser converter) for running at higher elevations. After breaking several stock 1.82 gearsets I ended up with 1.76's in the primary trans, have not broken a set since then (knock on wood). After eventually breaking the aftermarket 1.96's, I changed that trans to 1.82's but eventually broke them. Only at high elevation was the gear difference noticeable. I run a 4.75 rear end gear (yes, it's a weird ratio), 32" tall tires, ladder bar rear and tubular a-arm front. With short (22.5") front tires it would red light anywhere. This was 16 years ago, running an old trans brake without a dump valve.

Since putting the car back together (just last week) with an aluminum-headed 481" and 25" tall front tires, I think it reacts about as quickly as it did before with the iron-head motor and short front tires. I have not run any pro tree runs with it, but it cuts the same full tree lights that it did before (assuming I am still leaving the same) as with the short tires.

In other words, with a reasonable rear gear, relatively short front tires and a modern pro-tree trans brake, you shouldn't have any problems.

Regards,

Bill Webb · 07-22-2009, 08:12 PM

1.80 most definitely Dont mess w anything else

63corvette · 07-23-2009, 02:31 PM

I build racing powerglides and from experience you will not know the difference.
Just buy a good gear set from a good manufacturer.
Stay away from the 1.82 stamped housings. They will just not last even with a small block.
My 2 Cents

07-21-2009, 06:14 PM	#1
hotrod1446 Junior Member Join Date: Jan 2009 Posts: 15 Likes: 0 Liked 0 Times in 0 Posts	Super Gas Powerglide low gear ratio 1.76 or 1.80 I have a 2700lb Super Street Vega which is powered by a SBC, runs 9.80. Blew the 1.82 planetaries and looking to buy a replacement tranny or gearset. Looking to get opinions on using 1.76 or go for the 1.80. Will use pro brake for the few 9.90 races but will race 10.90 most of the time. Ladder bar with coil spring front suspension. Will the 1.76 get my lame small block off the line quick enough for pro tree racing? __________________ www.EngineHones.com

07-21-2009, 07:34 PM	#2
Michael Pliska Member Join Date: Oct 2008 Location: Happy Valley, OR Posts: 260 Likes: 0 Liked 0 Times in 0 Posts	Re: Super Gas Powerglide low gear ratio 1.76 or 1.80 Granted my car was lighter and with a big block, but I found negligible difference with the 1.76 versus the 1.82. Mine is a Super-Gas Vega with a 481" motor, with iron heads the car & driver weighed around 2350. When I first put it together I used a 1.82 for most conditions and had a 1.96 trans (and looser converter) for running at higher elevations. After breaking several stock 1.82 gearsets I ended up with 1.76's in the primary trans, have not broken a set since then (knock on wood). After eventually breaking the aftermarket 1.96's, I changed that trans to 1.82's but eventually broke them. Only at high elevation was the gear difference noticeable. I run a 4.75 rear end gear (yes, it's a weird ratio), 32" tall tires, ladder bar rear and tubular a-arm front. With short (22.5") front tires it would red light anywhere. This was 16 years ago, running an old trans brake without a dump valve. Since putting the car back together (just last week) with an aluminum-headed 481" and 25" tall front tires, I think it reacts about as quickly as it did before with the iron-head motor and short front tires. I have not run any pro tree runs with it, but it cuts the same full tree lights that it did before (assuming I am still leaving the same) as with the short tires. In other words, with a reasonable rear gear, relatively short front tires and a modern pro-tree trans brake, you shouldn't have any problems. Regards, __________________ Michael Pliska 643 S/G

07-22-2009, 08:12 PM	#3
Bill Webb Junior Member Join Date: Jan 2003 Location: Ohio Posts: 73 Likes: 0 Liked 0 Times in 0 Posts	Re: Super Gas Powerglide low gear ratio 1.76 or 1.80 1.80 most definitely Dont mess w anything else

07-23-2009, 02:31 PM	#4
63corvette Senior Member Join Date: Mar 2007 Location: Canyon, Tx Posts: 538 Likes: 120 Liked 295 Times in 90 Posts	Re: Super Gas Powerglide low gear ratio 1.76 or 1.80 I build racing powerglides and from experience you will not know the difference. Just buy a good gear set from a good manufacturer. Stay away from the 1.82 stamped housings. They will just not last even with a small block. My 2 Cents