I have heard a lot that power glides dont live behind a heavy car. Like much over 3000 lbs. And in a 2800 pound car, with about 575 hp and a 5.29 gear leaving on a brake at 5500 rpm, what do you think you sould expect for an et difference, from a th 400

I've got a ton of runs on my glide at 3250 lbs at 900+ hp.

They are running in 6 second 200 mph plus Drag Radial cars at 3500-3600 lbs. Course those aren't stock powerglides either, let's just say they certainly can be built to hold up in a heavy car with tons of HP.

988 hp @3600lbs with a JW glide

I've never ran anything but a glide, I'm 3200lbs only hurt one tranny, and that was a stock high gear clutch, (I knew better). With decent parts a PG will hold alot of power.

Right now I'm making around 1500hp and the glide is doing just fine.

When I ran 10.0-10.4s, we used a stock case and gearset, I ran that combo for 3 years and never hurt it.

About an ET differance, I dont think you will see one, as long as you have the right converter in front of it.

In a bracket race a 2-speed is more predictable than a 3-speed, they dont care as much about track conditions or suspension errors.

I here the same thing Glides are good for under 3000 lbs. Well let me say that it depends on the Glide and how its built.

Alot of MONSTER TRUCKS are running Glides and there tires weigh 3000lbs so I would think the 3000lbs rule it out.

A couple of years ago, a friend who ran a 3500# El Camino w/TH350, lost his third tranny and asked me what I thought of changing to a glide. I recommended that he try it, since he already had a couple in his shop. He changed to a turbo input, in one, and has ran it ever since. It also picked the car up a little over 2 tenths, from the get go.

So with a car with 28 tall tires and 4.30 gears launching at 5200, would i need to switch to a lower gear to make it work right?

If your rear gears were right with the three speed they will be right with the 2 speed.

They are both direct drive in high gear, you figure out what rpm you want to turn in the traps and make your gear/tire diameter meet that number.

WDCreech is right, if you run a glide use the turbo input shaft, they cost the same and they are stronger, I've never broke a PG input but I've seen many twisted badly.