After more research, I'm practically more confused than i was/am. Alright, my 1989 AT needs (a) head gasket.. while I'm removing the intake, and 1 head, I'm going to do both gaskets with ARP head studs. While the aluminum(never knew that) heads are getting checked for straightness, cleaned, and a valve job, I want to install a good set of valve springs (In preparation for a cam, injector, and PCM Upgrade). I'm not asking for a spring rating, brand.. I'll purchase what the cam manufacturer recommends, but what PLATFORM, or BRAND, should shop for? sbc 1960-1987? Now I know it has a 1 piece rear main seal, aluminum heads, and I even believe roller lifters! Are the L98 aluminum heads valve spring diameter, the same as 1.94/2.02 old school heads?? What do i shop for, when it comes to L98 aluminum heads...

Something else I cannot seem to find, what's the size of the L98 intake, and exhaust valves? 1.94??

This forum is priceless, and even though i haven't laid eyes on this 1989 (It'd pai for, filthy, and is getting scooped up this coming week) i plan on becoming a productive member of this site/forums.. Any sort of help is greatly appreciated.

 

OK,
I'll be the first to tell you that the Factory Service Manual (FSM) is a must if you are doing your own work on the car. The forum is the best I have ever been involved with and the folks here really know the C4. Ebay is usually the best resource for the manual. I have had my manual for so long I don't remember what I paid for it. I think the average price now is around $80. Get one for your specific year.
When I bought my 86 it had the same issue as your 89. My aluminum heads came with the 1.94 intake valves. I cannot say for certain that the 89 year is the same but I imagine it is. I have since upgraded to high flow heads and intake.
Sorry, not a lot of help I know. It will be a slow weekend on the forum because of the NFL playoffs.
Congrats on your purchase. I hope you enjoy the new toy as much as I enjoy mine.

 

Jazfe:
What heads did you use to replace yours. Would a set of 2.02 "Double Hump" heads, have the amenities to accommodate all of the Corvettes accessories? Like A/C, and everything that bolts up? Or what about World Product? Angle plug, 2.02.. cast iron, but that doesn't bother me. I will hop on eBay, and have a peek for an 1989 FSM. This isn't the first platform I've gotten myself into.. lol.. and when I began on those forums, FSM was recommended. But!! this is the first V8/RWD combination I've ever had. lol.. besides driving my dads truck, or moving one at work, RWD/V8 on the street (Not dirt oval), is my first attempt. I really appreciate your reply. Is there a low cost (LOL) intake manifold solution? where would I look for the PCM? It seems v8 isn't supported from what I'm seeing. Thanks again!! And it's cool now-a-days, books, guides, reference material, can be retrieved in no time. But nothing beats "The Real Thing" (:

 

Stiggity99,
It's been a few years since I did any research on heads but I seem to remember the heads on your car flow better than the double humpers. The restriction on the TPI engines is the intake. But it sure makes up for it in low end torque.
Your car should have 10088113 heads: 1988 through 1990 350ci Corvette. Aluminum, 58cc, angle plugs, raised runners, d-port exhaust, 1.94 and 1.50-inch valves.
If you are on a limited budget then getting the heads checked and new valve seals and gaskets will get you back on the road.
As much as I like to wrench on my car I enjoy driving it more.

 

Jazfe:
If i have both heads off, wouldn't taking the motor mount bolts out, and raise the engine a few inches, remove cam, lube up new one, and install....but then again, i would need to remove water pump, timing chain cover, harmonic balancer, belt pulleys... idk what to do? I am on a limited budget. I tucked away enough to get heads magnafluxed, cooked, cleaned, 3 angle valve job, install new Bee hive valve springs, a super nice set of valve seals, a gasket kit from heads on up. But, even with those 2 questions, lets say I install the infamous, Hot Cam!!! will my factory injectors become my next bottleneck, and will a 100% stock ignitions, and EMS system run half decent with that cam? And im only referring to a camshaft that's a popular aftermarket choice. I have no dead line, and money comes in each week...(not much (). Now that you sort of know what I'm up against, and you actually drive your corvette, what should I do? I have a 280HP v6 daily.... but a friend of mine, owns an exhaust shop down the road, and he said he'd put a wicked setup on it on the cheap (Pipe bender, welders,lifts,pipe in stock, mufflers, etc.. so that's covered,, and what do you do if you install a set of headers?? All of those hoses, and vacuum lines running from the factory exh manifolds... or should I retain the factory exh manifolds? I'm aware headers are the solve all for a muscle car.. LOL.. but don't they usually end up having leaky gaskets, rusty pipes.. Or can anybody recommend ,not a $1,000 set of headers, but a nice set that drop in, give a little, room to put plugs in... Headers? Yay/Nay....delete factory emissions and smog hardware?? yes/No? ...(Is it possible)? install cam while heads are off? the odd thing, if I begin in march (When things begin to warm up here in PA), and install a cam, i'll just put a little money every couple of weeks into it. But if I Just have machine shop check heads for straightness, cook =, valve job, and install springs (I forget the cost of 1 head, let alone two!) get some arp head studs, and a gasket kit... then! I can drive it.. Hmm... I'm sorry for the slang, and improer terminology. And before I compose a small novel.... Jazfe?? whats your input? anybody else getting into there very first V8/RWD and/or,=, Corvette!!!!!! Im installing a neww water pump (Thats why i wont be able to drive it right away... it was overheating, and he parked it. I figure flush the radiator, and put a thermostat and water pump...but!! Mmmmm... RIGHT theres the timing cover..

 

OK.....just my 0.02's worth here (keeping in mind you need budget friendly), let's start with the heads! First, I wouldn't go from aluminum to cast iron heads, the major reason is aluminum heads allow you to run about a full point more of compression (notice the 58cc chambers) before running into detonation....use your factory aluminum heads! Valve job, seals (make sure they're the good positive-lock type), and resurfacing (make sure only enough to make them true, otherwise you'll need to calculate some thicker head gaskets) all good ideas....the springs need to match the cam, not be limited on cam choice because of the springs you put in! Fitting the springs properly often requires machining the heads for proper depth to achieve the proper installed height....you really should do the cam change now if that is 100% what you want, all the work of disassembling and reassembling the top-end, water-pump, radiator, etc you'll have to do AGAIN, not to mention new gaskets, setting timing again, etc! You need to pick your cam, so you can pick the right valve springs. Since the timing cover has to come off, the oil pan really needs to come off as well!
Couple last things, the ARP head studs are definitely top-notch and awesome but very spendy, you could repurpose some of that money and go with some ARP head bolts instead. After all the advice you've received, there's some questions that should have been asked to begin with:
How many miles on your car/engine?
Overheating Issue???? Please explain that entire situation....how hot did it get? Any coolant in oil...oil in coolant?
Haven't even addressed the headers question....depending on the miles and overheating story and how deep you're going into the engine, it might be time to get the engine on a stand! Right now you need to reevaluate the entire situation, assess your money budget and time you have to work on it and get a solid plan that you can execute, so you don't end up with a Corvette in boxes!!!! If it were mine, I'd pull the engine, evaluate the health of the bottom end and if all checks out, put your new cam in, get your heads done and put it back together (much easier to torque things down like heads out of the car, etc)! While the engine is out, pressure wash the entire engine compartment/front suspension, pull the radiator to clean in-between it an the AC condenser....you have your hands full, do things once, do it right, be done with it!!! Good luck👍

 

78corvettes.a.,
Thats exactly what i want to do!! Then i can work on the engine indoors (Put it on a stand). And to be honest, I'm picking the car up This Friday!! about an hour north of me. It was her dads, and his wife and daughter (I'm communicating with the daughter), if the one who posted the ad. She said it doesn't run due to the battery being dead. She also stated it needs washed, and a head gasket. So, I'm spending 2-3-4 hrs each evening reading on all i can find. It has 80k miles, Auto. 1989. She said her began overheating on him ,so her took it to his mechanic, and then was told it needed a head gasket. I hasn't been inspected since 2019 ad is very "mossy" LOL!!! even been watching detail inside&out videos.. ehehhe But, its only 3 days now. I want to drive it, but..im going to pull plugs, put some AT fluid in cylinders, or PB Blaster. some sort of rust lube. *in case the cylinder(s) that wee burning antifreeze are all rusty (Been sitting 4 yrs), drain fuel tank, remove fuel line at rail and blow ir thru, install new fuel filter. And first thing, change the oil/filter. Put fresh gas in it, new set of plugs, and see if it starts... i guess the first thing is se if it's locked up. But i don't think she wouldn't have told me if it was. The car is in her moms name, it parked at her moms house. going to be an adventure. And Yes, i will be removing engine. The only bad thing (So faar... ) the car has a set of American Racing, 17" rims now.. I wish the stock 1989 wheels were there, but nope.. I did get in contact with an outfit to burn an epromp for the ECU... $370!!! and i have to give them some sort of code somewhere. In the glovebox? thats next month.. if itstays in mid 40's to low 50's i'll have the engine out in a couple days.............

 

Im seeing this L98 has roller lifters? Should I reuse them?. I could get them cleaned at the machine shop, re-install with a Edelbrock roller cam? or should i get new lifters and not use 80k mile stuff in a car im re-doing to be reliable... What's your thoughts on the roller lifters?

 

im having a hard time choosing the camshaft. I know what lift ad duration are, but will it idle with a stock converter?? ANd i dont need a 3500-8500 power band ehehe.. whats the most aggressive cam/lifter kit that s has a 2000-6000rpm? 1500 to 6000RPM power band. I also read the rea end gear ration is higher than the 6spd? 3.07 vs 3.32 i think.. if i need a converter, Hrrrrmmm.......

 

Sorry for 3 added quick responses..can i run a different timing chain cover? and/or will the factory cover allow for the width of a double roller timing chain?

 

I know with the little bit of Muscle Car experience (A long time ago.. ) usually we'd remove the hood, so the hoist doesn't hit it, & allows more room. Can the engine hoist lift the engine out over top of one of the fenders, or am i going to have to remove the hood. I surely hope not. I've seen videos of folks lifting there long block up an inch or two, to R&R there camshaft. 78CorvetteS.A?? I appreciate your advice, and it comes off as genuine. Wasn't aware of the 58cc heads. What kind of timing am I shooting for?? 35degreees?? HAHA <jk> I'm capable of remove/install distributor, I see there isn't a vacuum advance.. HEI distributor. She will drink 93octane, and be cared for. Found some shocks that I'm thinking about getting. sometime down the road. I have a stand, hoist, tools, air, torch, welder. Lift, lol. but I cannot tie it up during the work week. It'll get done, and the sooner the better, but I'm shooting for a late spring, early summer end-goal! we'll see.. and if the cylinder(s) that were leaking, are 4 years worth of rust, I will at least get block magnafluxed, washed , honed hopefully, cam bearings, and freeze-plugs, also measure rods/main to see if this has been worked on previously. All it takes is labor, and money. The cool thing, the machine shop is the same that built my 4g63, and g54b... never an issue at all, and labor is more then fair.. but this was 2014.. almost a decade later.. there still there, building engines.. re-doing heads. They have an awesome deal on a Magnaflux, mill, cut 3 angle valve job. Assemble. Welp, back to the real world... for now.. thank you 78CorvettS.A.

 

It started to overheat and a mechanic said head gaskets? I'd be looking at that first.

You need to get your mind out of the 60s. Double humps are meh at best now.
I would definitely do the cam swap while you have the top end apart, and if you think you might want to swap cams again I'd look at a two piece timing chain cover

Most importantly, figure out what your goals are, horsepower and budget. Spend the money where it counts the most. (Another reason for the cam swap now)

 

64scout
The one I saw on JEGS is $350? Will a regular double roller timing chain not clear the timing cover? Or is there a nice, single chain I could use? eBay has a bunch of 2 piece, (Like ~$30 - $50) but they don't even resemble the one I looked up on the Jeg's website... could you possibly clear up the confusion. I wasnt ever aware there was a 2 piece... until i read that a few weeks ago..

 

My plans/goals for the car is, retain factory 80k short block, rebuild heads w/springs/retainers/keepers, 2400-2800 stall converter, camshaft, timing chain (2 pc cover?), oil pump, 2 good head gaskets, ARP heads bolts, a complete engine gasket kit, new pushrods, roller tip rockers, 26lb/hr injectors, and a custom PCM from one of the remaining suppliers, with a good name.. headers, no cats, but retain all o2 sensors. Remove all smog, and EGR, reduce vacuum routing to (what's needed), a new cap, rotors, ignition module, plugs, wires.... w/e that results too, is my goal. I probably forgot something/or other. but that's the plan.. i have no deadline, but would like to drive it in the summer... or early fall. A/C is staying!! w/e i need to fix, charge, use it will be done. And!!! does anyone know what vacuum sources the blend door NEEDS to function right, after the smog stuff has been deleted... like does it JUST require a source, or both source, and loop back.... the car is 100% stock, except full exhaust. (DC Sport)and i cant find it online. not even rusty.. if someone ca/wants to chime in, your input is greatly appreciated.

Where's everyone getting there injectors? I've been on eBay, and i see (8) brand new, from USA @ $78 ?? what in the heck is that all about. I want to source a set of 26lb/hr units... used or new. As long as they check out, and are worthy of doing the work, time, PCM... again, Input is greatly appreciated.