So I’m considering a rebuild on my 1985 L98. There are some problems in the cylinders that I’ve not fully been able to diagnose, but also some gasket issues and Oil leaks/consumption. Car still runs and drives fine, but is developing Enough issues that I know at some point I’m going to have to do something about it.

I’m planning on sticking pretty close to stock. I don’t race the car and I don’t want a bunch of reliability issues. I just want a solid engine that I know is going to last me.

That said, is there anything I should have done while I’m in there? I’ve read about boring the cylinders out to 383 for more displacement/power. On an otherwise stock car, is that a good idea? or am I inviting problems by doing that. Again, reliability is more important than power, but power is nice if all else is equal. I’m certainly not looking to break the bank. Overall I’m happy with the car and enjoy it.

thanks!

 

GMPP sells some nice crate engines , check out pace performance...summit racing sells some of them also.
383...best if you get improved heads/intake/cam but sure is fun with all the extra torque.
Nothing wrong wtih a nice 350..better heads/roller cam it will feel like a different car.
Half decent 350 from gm starts arond 22-2600 and 383 little over 3 hard to go wrong everything is brand new. Lots of options, theres 1

 

I’m looking at $1500 for a rebuild from a local guy who is well known and respected for his ability, so that’s going to be a LOT cheaper and plus it’s the original engine. I’m being boring out to 383 would cost extra but still probably be cheaper overall.

if I put the stock intake/heads/cam back on with it bored out-would that cause issues? Or would I just be missing out on some power?

 

It would be a 0-4000 RPM tork monster.

 

sooo... you’re saying I should go for it? What would be necessary to make it work? Any other parts? A tune chip? Or just drop it in and go?

 

A 383 is a 350 block bored out .030 over with a 400 crank which has a 1/8" longer stroke. You can't just bore out your motor to make a 383. I would just rebuild the 350. Maybe bore it out .030 to clean up the cylinder walls. You will have a 355 motor. You won't have to change anything else. If you start messing with internals and displacement, you will have to deal with tuning which may be easy or not. If you aren't racing, just clean up the heads, clean up the cylinder walls and new rings and bearings and you'll be fine.

 

I wasn't implying that you should do it....just stating what the outcome would be with a 383 and a stock intake.

 

If you want just a 1500 buck rebuild throwing a small cam at it is cheap and shouldnt throw fits with your computer. Would be a shame to do all that and not pick things up (dart iron eagles are cheap)
that and a simple bowl blend will help, doesnt cost much

To make a 383 worthwile improving the exhaust intaek heads shouldnt be passed over that will put you way over budget.
Headers/gears are a quick way to up the fun factor

 

thanks for the advice guys. I guess of Im spending the time/money I want to do it right-but that can really be a rabbit hole that can get very expensive. I really like the car as it is, just don’t want to push it hard because I’m worried it’ll just completely let go on me. Having everything rock solid stock is good enough for me. Just don’t want to miss the opportunity to do minor upgrades that are worth doing if Im in there anyway. What I’ve read has typically been “the more you mess with it the more problems you should be prepared for”. I’d rather just have zero problems and get to enjoy it.

 

i agree that the while u r in there rabbit hole is important to steer clear of unless u r performance driving.

couldnt u just hone the cylinders, new bearings, new rings and new gaskets and call it a day? that sounds like about $1500 worth of work.

 

Yeah that's probably what I'll do. Like I said, the goal isn't a race car, it's a relatively reliable fun driver. Stock L98 is already pretty fun to drive.

Thanks for the advice guys. May be a minute before I actually get to doing it, but trying to put together my plan.

 

a 383 build only really gives you around 40 more pounds of torque over the same thing in a 350 build doesn't it? i mean if you put all the same components in a 3.48 stroke crank vrs the 3.75 stroke crank.. and by the way, they guy who said dart iron eagle heads are cheap/ yes but the dart shp aluminum heads are even cheaper i think. mine were anyway.. but 1500 dollars is probably not going too involve a new set of heads. if i had a 1500 dollar budget i would aim for a cam upgrade new rings bearings gaskets, 85's didnt have the 113 head, correct? so maybe find a cheap set of those used and go through them for cheap. i think you can find a used set for a couple hundred and they reallt are decent heads in stock form. one of the best chevy heads they ever made i think 85 had the forged pistons with slightly lower compression due the the other heads? so the 58 cc 113's would be a nice little upgrade there also?
regardless 1500 dollar rebuild is a tight budget but very do-able
cam kit with springs timing chain and lifters is pushing 1000 alone. then a new oil pump is about 100, rings and bearings will be another 150 ish pretty much there i guess with that, not a total new rebuild with bore job but if the engine is running you might not need anything else but a rering/refurbish
good luck with it.

 

i am not trying to hijack your thread in any means.. but this pic is what i have been doing ALL summer long and buying things as my wallet allows. this is stock crank/ rods and pistons. same oil pump with new high pressure spring. i have about 2 grand or so into it as it sits with a new lunati .515/.530 cam and dart shp 180 heads and the air gap rpm intake with holley ultra d/p 750 cfm. so what you are planning is.. doo able really. just re-use all the stuff you can re use. my cam has a rpm range of 1800-6200 and i am thinking like you. it isnt a race car i will never have it on a drag strip, i just want a good runnign fun to drive car that has decent power.. a desktop dyno rated everything i have in it at 410 hp and 425 torque at 1000 feet elevation with a 75 degree air temp day. with hooker headers and full exhaust system with mechanical water pump... which i just bought a proform electric on today for it so a few more hp and torque above those numbers for me... plenty of power to have a lot of fun with for cheap.

that 2 grandish even included lunati full roller rockers too

it is not hard to rebuild an engine really. might be a fun project for you and save yourself some cash

 

you would be missong out on some serious power imo.. not the 383 part just the stock intake heads and cam parts

heads alone are the ticket for good power gains but you need a cam with the lift to use those high flowing heads. even with a stock size cam you would have good gains from the better flowing heads and not just any heads you want efficeint flowing heads, meaning you want the exhaust to flow about 80% of the intake or more. those 113 stock heads are a very efficeint flowing head as stock for under a 500 lift cam they really are nice, like i said you should look for a set of used ones unless you already have a set but 85 did not come with 113's from what i have learned here

 

From what you are saying above I'd 100% just do a stock rebuild. Do not do a cam upgrade or head upgrade unless you also plan to upgrade the exhaust and potentially the intake as well. Keep in mind the 85 computer is slow and quite honestly doesn't "correct" to well for anything more than just some exhaust mods. I added TPIS headers on my stock 85 and things ran great. Engine got tired so did a ZZ4 swap (basically your engine with a mild head and camp upgrade) and the stock computer never allowed the car to run as well as it should have. You can swap to something like the dynamic EFI for pretty cheap (about $600 all in) but as you can see, you are now already in the rabbit hole.

Just rebuild the factory engine and have fun with it unless you want to do other supporting mods too.

 

thats why i am fine with the carb.. obd 1 lacks of alot of modern era stuff for good fuel injection imo like a 1984 apple computer vrs a modern day comp. plus simple. sure you can't use a remote start with it but so what

 

I just finshed rebuilding my L98 and am breaking it in. Same reason, budget and I'm already having fun with Her power. Though in my case, I am seeing some improvement since Her compression was a bit low before.