My brother is looking to get a 87 GTA with a 350 TPI auto what would it run rock stock in the 1/4 considering it is in perfect working order?thanks!

 

High 14's.

 

exactly

 

In Perfect working order My 87 Iroc 5.7 ran Totally stock high 14s (right about 14.7) to 15.1s (when the weather was hotter then hell) & that is at tracks that are at 500 above sea level & at sea level.

 

I've seen them run faster than that. If it is a strong L98 it will run mid 14's with a good launch. If it were a speed density L98 I'd possibly say low 14's on a perfect day, but SD's are only 90-92.

My GTA with a swirl port heads, and a peanut cam ran 15.3 @ 87mph. Any properly running L98 should move much quicker than that.

 

hmm... stock they'd run 15.5 or so because they're so damn heavy. i would venture to say that if you put brand new plugs, wires, cap, rotor, coil, and an msd box, you could run around 15.5, +/- a tenth of a second or so. but do you think a car that ran 15.5 18 years ago is going to run 15.5 today? ... i hope not. when i got my car (1990 iroc-z L98 g92) i was expecting low 14's after i replaced the cap/rotor/plugs/wires. it had a 80 series flowmaster on it as well... but it ran a few 15.1's before i figured out how to launch that sucker and nailed a 14.8. took off the cats and she ran a 14.5. shave some weight off that gta though because, like i said, they're heavy SOB's. good luck to ya

1/4 mile time found here: http://www.ssmoparmuscle.com/speedcomp.htm

 

Mine GTA came in at 3,389lbs with a half tank of gas. That was stock with no mods. Motortrend had a 1987 L98 Iroc-Z run 14.5 @ 95mph. 91 GTA L98/auto ran 14.4 @ 96mph with a 2.4 60' at US 41 in Morroco Indiana.

My GTA pulled 15.3 @ 87mph with a 2.023 60' at Rt 66. This was with a bad EGR, 1 leaking injector, TBI heads, and a TBI cam in 350 roller. I had bought a long block and it had TBI heads/cam from a TBI caprice 350.

There are slow ones, and there are fast ones. But not all L98's are 15.5's, nor are they low 14 second beasts. A 14 second run should not be unexpected.

 

In missouri i would think you would be lucky to go low 15s

 

87 GTAs COULD BE HAD with the wee little 305 in 87, don't forget. I think they were 5-speed only cars. Maybe they had some 305/auto GTAs, but I can't say I've ever run across one.

Some of those GTAs, depending on options could get QUITE HEAVY. Brother had an 87 tipping the scales well over 3600 with power seats, power everything, plenty of options.

Seen 'em run mid 15s more than once. I think a 14.99/15.00 would be more typical. Mid 14s would be something very special. A 13.99 just ain't gonna happen.

 

put a shift kit in it...a set of headers, cut the bottom of the air box and put some k&n air filters in it, and if you venture to a set of plug wires....and you will see 14s for sure +/- a few tenths

 

and if you have no emissions cut the cat....you will see big improvements the key to the tunned port is let the air come in and out with some simple mods...you will see the most hp from this...and alot of the mods are basically free...

 

The most commonly produced GTA is the 305/auto. Despite the fact that GTA's came standard with the 5.7L/Auto combo. The rarest of all are the 305/M5 combos.

305TPI auto GTA's are dogs. They can barely crack a low 15. The reason they are so slow is because 305TPI/Auto combos received a peanut cam with less duration and much less lift. 305TPI/T5 cars recieved the L98 cam which actually has more duration than an LS1 cam.

If an L98 car is running a mid 15 then something is very wrong with the car. There are plenty of L98 and LB9/M5 cars pulling mid 14's. I've also seen some incredibly fast L98 cars that have no right to run as fast as they do. One of the local guys cars, a 91 GTA 350 put down 225hp and 315lb/ft to the wheels. The L98 for that year was only supposed to put down 245hp at the crank. When he drove it at US41 he ran 14.4 @ 96mph with a 2.4 60'. With a good launch it should amost crack 13s.

So yeah, there are slow ones and fast ones, but mid 15's is way wrong for an L98. Even a 15.0 is too slow for a good running L98.