gearing and brakes

ok so i have gotten the codes off of our rear end and i have been able to find out that we have a 3.08 rear end.

we also have an M-20 muncie with the following gearing
1st. 2.52 2nd 1.88 3rd 1.46 4th 1.00

now im no enginer but these ratios look terribal, they might help me kill my self at high speed but i know the rear end is geard way low and the tranny seems to be the same way. will this combo support 500 plus horsepower?

since it wont be fast off the line anyone know how to put these ratios into an equation to get the cars top speed and acceleration.:iceslolan

What you have is a "wide ratio" Muncie. It allows the use of taller (lower, numerically) rear axle ratio, and still have a semblance of "off the line" power. The M-21 was the "optional close ratio" version, usually with 3.55 or lower (higher, numerically) rear gears.

The horsepower is no problem. It's the torque that will kill it. If you're talking a 500 HP Pontiac, you're also looking at well over 500 lb. ft. of torque. If it's just a small block pumped up that far, it won't make near that amount of torque. We've been breaking more and more M-22s of late, with our power packages (street racers are getting around 600 HP now, 93 octane). One of our better guys ('65 GTO ragtop, 3,810 lbs. race weight, 11.34 @ 120.5) has gone to the Jerico version of the Ford Top Loader, as he has destroyed several "Super Muncies". It's a true street car, but he's been racing it more of late. You can see it on our site's front page. (centralvirginiamachine.com)

Jim

Yah its a hot 455, i was told we would cook 1,2,or 3rd gear in that tranny in no time. Iv been looking for a solid salution but havnt found an affordable one yet. I will be using the 455 at the track and the 389 we have (400hp-400 plus torque) on the street. If you have any easy salution let me know. Iv looked at aftermarket 5 spds but i dont know which one is reputable. After searching iv only found 1 or 2 that go into the 65 gto and they all require special shifters. By special do they mean fabricated or are these conversion pieces available through the retailer?

For power levels above 500 HP and lb. ft., we ONLY recommend the Richmond 5-speed. That's the "street version" of the old Doug Nash race trans. Both Richmond and Hurst supply a shifter for it.

The Tremec "T-9" has gained popularity, but reports behind high-torque engines have been less than satisfactory. The Pontiac is a bit tougher on transmissions than Chevy big motors.

The "Super Muncie" (supplied by an Italian manufacturer) can be had with various gearsets and is much tougher than the standard M-22.

Jim