L98 is a good motor. LT1 has more squeeze in the holes than L98, and the higher the squeeze, the sooner it's gonna' wear out.

Before mods comes tune. Read the TPI tech thread I just posted. Some think there's some mistakes in there, but even if there is, the tech info is very valuable.

 

I have done many of the freebies that everyone has listed thus far, but
by far the best bang for the buck has been the Hooker 02149's LT
headers, true dual conversion-2-1/2", with B&B muffs, high-flow bullet
cats, and an x-pipe.....sounds mean as hell, and definitly freed-up a
bunch of ponies. It's also a building-block for anything else you do to
enjoy your ride more....I also have an 89 Coupe, and I love it!

 

i live in missouri and not to sure how emissions work here but i know some guys that can inspect it for me and what not. would it be better just to go with straight pipe or hi-flo cats? and also would it be better to have a full exhaust system or dump em at the axle? thanks alot guys youve been a big help and as soon as i get ahold of my friends camera ill get some pics

 

What you "should" do depends on the goals of your car. If you're going to leave it stock (w/o heads/cam), then leave the cats on in some shape/form. Will help to redo with newer, better-flowing cats though. Cats muffle too. No mufflers with just cats sounds reasonably loud/aggressive.

Don't terminate the pipes under the car. Fumes can get in your car and it would create resonance in the car... bad idea.

 

ok, how does your side exhaust work out?

 

Better than terminating under the car at the rear axle.....

As far as sound, I have front and main "hiflo" cats. And, I repacked the factory side-pipe mufflers with 2000-degree adhesives and fiberglass batting. (But the SP mufflers still don't do much.) The whole setup sounds good. Not anywhere near loud, but "sporty" nevertheless.

Without front cats, it was loud (especially inside the car). Sounded more like a race car.

fyi: The cats are all magnaflow. Fronts are rated for 4.0 liters each. Main is rated for 7.4 liters.

 

I agree that it's an "old motor" but the "free" mods don't cost much and some can be carried over into a rebuild or even a crate and the exhaust surely will go with whatever is done with the power plant.

 

That's one if the things I meant by asking about your plans. The intake/exhaust/headers are external from the motor and can be reused -- if planned ahead. Those parts together could run you over half what you paid for the whole car.

 

i want just a nice street car. i have an ecklers vette mag and i figured up alot of figures while i was bored at work and came up with 400 hp at 2600 dollars. im pretty sure about 85% of the mods i could reuse. but im new to vettes and also im only 20 yrs old so i dont know a whole lot. my car dont sound to bad so ill prolly just DD until i save up some more money and rebuild the engine or get a little more powerful one.

 

If working on a tight budget, buy a complete LT1 exhaust system, used, and bolt it on. I've researched alot and that seems like a nice upgrade and one can be had very cheaply ($50 to $100) in the for sale section. I have true dual exhaust now going into my factory catback and am upgrading to an LT1 catback myself. Long tube headers with an LT1 exhaust will give you a nice bump and can be re-used with a new motor should yours ever blow, but the price for long tubes and an install can be upwinds of $600, or more if you get fancy with the headers. Next, see what gears you have in the rear. I'm assuming it's a D36 rear, but don't know. If you have 3.07's then leave them alone. If you have 2.59's then either buy a used 3.07 differential and swap it out, or buy 3.54's and have someone install the gears. That will be another nice mod that will be great with your old engine or with a new one. Underdrive pulleys are cheap and easy and help these cars alot. Remove the disc on the front of the water pump too. Get new plugs and wires and such if they haven't been changed out in a while. Clean the junk out from between the radiator and condenser, it will be full if never cleaned before. With the mods mentioned that thing will feel like 75 to 100 more horsepower. Ecklers and the like put hp figures that are so far out of whack they should be sued for false advertising. Don't go by their figures on their parts at all.

 

Put corsa exhaust on my 89. Quiet crusing, loud wot. Sound great