Hey all, I got a scenario for ya. You just got an 89 IROC-Z a couple months ago. It has a 350 engine in it. Has the auto tranny to it, and has 2.77s rear gears (if that makes any difference). The engine is on 108,000 miles! Its in top condition, sounds great with the hood up. People can't believe that it has 108,000 miles or the fact that its 13 years old. It does NOT burn oil. It does NOT smoke at start up. Everything seems to be just fine with it... now... what would be your future plans with it? What would you DO to it? What would you NOT DO to it?

 

I would get a set of headers. I just put a pair on my car ( i dont know what brand they are, i bought them used, but ive heard dynomax, flowtech and headmen make shorty headers for about $100 that work well). My little 305 will scream happley to 5000 now, before them at 4300 it sounded pretty bad. I would definately great as much done to the throttle body, plenum, runners and intake as possible. This guys site shows some of his work on that stuff, http://www.cis.udel.edu/~davis/z28/buildup/plenum/
The intake mods and whatnot will help your engine pull to a higher rpm ( stock tpi setup is supposed to only be good to about 4500). I would also recommend a bigger cam. If you've got the money id say go for a hot cam, But if you dont have alot of cash id say just try and pick up an lt1 cam off of ebay or somewhere. You should still be able to keep you stock stall converter and it shouldnt mess up you computer. ( Id ask Vader or Damon about that just to check). Id also consider a shift kit. I put one in mine at about the same mileage as your car and it works great. It also makes the car alot more fun to drive. Good luck

 

i would modify it.

 

Yeah, but what exactly would you do?

 

What's your budget.
Get some headers (SLP being the best), Hooker cat-back, higher stall TC, 3:42 gears and a cam change, that would put you at very low 13s I would think with the right cam and TC.

 

I'm with mark. Headers, catback(i'd go full SLP if possible, or else what mark said, SLP headers and hooker catback). Heads, cam, SLP cold air induction. Gear swap. That should shave a big chunk off your ET.

 

Since I assume you don't have all the money at once, here's the order I would go

with rought estimates of price
Full Exhaust $700 about
Cam $130
Gears $500-600 with installation
TC $300
Head work $40 if you do it yourself

 

i'd drive it and modify as i go, but some stuff to look into:

transgo kit
2500 to 3000 stall converter
full rebuild of trans when needed with kevlar band and race clutches
3.27 gear
random technology catalytic converters
slp two on the left cat back
slp 1 3/4 inch headers
custom burned chip
hypertech coil
accel 300+ race wires
march aluminum pulley set
fluidamper lightweight balancer
possibly cc305 or hotcam
fastburn heads
scroggins dickey intake
runner change
etc., etc., etc.

there is way more to list, but not worth the time since i'm assuming it's all to put an idea into your head of what you can do once you have the money. my recomendation, just modify as you go along and don't ask questions that don't have any positive answer since what i or anyone would do with that car is irrelivant to you.

 

Personally, after Headers & Exhaust, Id go from the ground up..

Rims & Tires
SFCs
Drop Springs
LCAs and Relocation Brackets
Shocks/Struts
Sway Bars
Strut Tower Brace
Panhard Bar
Tubular K-Member

Swap in a 5 Speed
Aluminum Drive Shaft
12 Bolt Rear
Bear Sport Brake upgrade all around

By the time I had all this paid for and installed, that 350 would have about 500,000 miles on it , so then its time to drop in a 406.

 

What kind of perofrmance or 1/4 mile times are you looking for??

 

Thanks for the list of mods! I was just curious of what YOU guys would do, if ya had my car, just to get a different perspective. Of course theres a budget and time in my way, but I was curious if you were in my position what would ya do. Ya know a scenario. BTW I already have Flowmaster catback, ram air, and k&n filters. I also wanted to see, if any of ya would rebuild the engine by now? Or wait for it to die off? Its running well now, just wondering when I might have to rebuild and stuff..

 

It depends, what would your goals be?! Your engine sounds like its running good and it doesn't need a rebuild, but track or G-Tech times (if no track is available) and stuff can tell you that. Don't you get low MPG or have you fixed that?? SFC's yet??

 

You've said your engine is runing fine. Here's what I'd do:

Headers: Go with SLP's. There is a group purchase for them on the exhaust board.

Gears: Get 3.42s in the as soon as possible. That will make your car a LOT more fun to drive.

Torque Converter: something with about a 2500 stall would be nice.

Then I'd start on your suspension:

Subframe Connectors: One of the best improvements you can make to your car. In fact, I'd probably make them my second mod after the headers.

Lowering springs: Yours are probably pretty worn by now. Eibach, Hotchkis, Jamex and others can help out. Not only will your car feel a ton better, but it will look better too.

Shocks and Struts: Replace em with what you can afford. If they're bad now, replace them before doing anything else on the car.

LCAs (Lower control arms) and relocation brackets: Traction is good

Panhard bar: See LCAs

At this point, I'd go back to the engine. If it still seems to be going strong I'd swap a good cam in it. If you are more patient, save up to build a new engine that will put out some serious power and last.

 

I'd change the rear gears 1st. Then I'd find another engine and build it, if you want performance. Any engine with those kind of miles IS TIRED. No matter what it sounds like. You start beating on it, it won't last too long. Might as well find another tranny core too. It'd be the next to go with a stout engine. And the list goes on & on. Ain't this fun.

 

if you can find a 3.42 gear for a 9 bolt i'd be pretty impressed mcconahay. as for the gear, the tc is more important than the gear. a higher stall speed has more effect and less wear on other parts.

 

Hey thanks for the replys.. I'm curious how many mile do you think my engine has left in her if I go easy on her? How bout if I go hard on her? Just want to be ready.
..IROCZTWENTYGR8, I still got bad mileage, haven't gotten tuneup yet, still too cold for my taste. No SFC's either. I like to save a lot before I spend. I'm not the type that gets a 200 dollar paycheck and then spends it 200. I'm the type who gets a 200 dollar paycheck, and then spends like 20 bucks... see what I mean.

 

With your budget of $20, I'd recommend.... Uhhh........

Fuzzy dice.

 

I'm the kind of person that gets a $200 paycheck and spends $250.

 

I think if you reworth the internals of the engin it will last forever. A buddy of mine had one with 97,000 on it redid the engine and it runs great.no probs and it has like 130,000 on it now.
First thing would be exhaust, that livens them up alot.
get a new cam.
gear depending on what you want. I would get a 4:10
after that tare out the auto and make it a stick. T56
then that car would fly...then you get expensive.
New pistons, and heads...really fast!