I bought an '84 trans am with a 454 , roll cage , frame connectors etc. the engine puts out about 450hp , 480 lb/ft right now the rear end is stock and someone suggested they cant hold power even if they're beefed up and said i should change it over to a different rear end with a 4 link. is this necessary??

What kind of times does it run, just like it is? What 60'?

People have these cars in the 9s with the stock design suspension. A 4-link is not necessary.

What rear end is in it? There's a couple of kinds of "stock" ones.

4 link is just plain and simple, not needed. You can run ANYTHING through a stock style set up. Assuming you are not talking about running 7s or somehing, hehe. There are VERY beefy parts out there made for big power. I would know I am building my car to handle the 500 HP from the small block. The torque arm needs to be chaned thrailing arms, panhard rod (if you feel like it) Then the rear. 12 bolt all the way. Good luck and read up some threads in the suspention threads. Great stuff about making your car handle whaterver.

I used a factory style suspension (aftermarket parts) and 10 bolt diff until I swapped in a TH400 with a transbrake. I didn't think even the beefed up 10 bolt could have took more than one hit off the transbrake so I also installed a 9". To solve the torque arm mounting problem, I put ladder bars on when the 9" went in. My engine at the time was pushing around 600 hp. I think I got it into the mid to low 11's with the 10 bolt and torque arm suspension.

An automatic transmission without a transbrake isn't as hard on a diff as a manual transmission. Drive it until you break something then decide how much stronger it needs to be.

Smooky Hall, Rick Head, and Jim Filipowski are all running 7 second 1/4 mile times on stock style suspension...four link is no longer needed now that people have taken the time to invest in the simple 3 link design of our suspension setup.

thanks alot guys , thats what i suspected. maybe a spohn torque arm and a big rear sway bar would help it hold up a little better, any ideas?? Also Im not planning any more engine improvements for awhile the car has plenty of power for a few years im planning on using it as sort of a daily driver and occasional strip use. I was also wondering if anyone has done or knows someone who has done a 454 swap like mine into a third gen? , im wondering what kind of mpg i can expect from this engine its carb, headers , victor jr intake , electric water pump and fans , aluminum rad. I've heard i'll get around 7mpg but i was expecting better in a lite and aerodynamic car like this.

These cars are not light. over 3200 lbs. Your Mpg will improve with all that electric stuff but it depends more on your gearing and even more on your tunning, not to mention the way you drive it. Fill in those pieces of data and people will be able to give a much better estimate.