Hey guys. I have a stock 1990 base manual that im looking to put some decent HP to the ground around 500hp plus is my goal right now maybe more. Me and my buddies have been going round and round on how this build is going to be. We keep coming with different prices over different things and im a person who isn't into wasting money on a build. Keeping it a manual is a must.
im back and forth on a 383 stroker with mods on it or LS swap it and do mods there.
I read that some people swap a carb in it and im fine with that. My main deal is keeping it a manual and getting the best bang of the buck. As of right now I'm doing my research first before buying parts as this is going to be a year long (2021) build on getting the parts. Any insite is greatly appreciated thanks

 

I would say you can get to your goal either way.

A couple questions for you:

Are you open to using forced induction or are you set on normally aspirated?

What's your intended usage for the car? Do you care much about manners and idle quality?

Having modded my SBC then done an LS swap some points to consider.

-If you mod the SBC most of the money will be spent on modding the motor. With an LS swap you spend a bit to get the LS running in the car.

-The LS oviously has more potential for HP but I think 500hp is achieveable with either engine. If you using forced Induction then it should be pretty easy either way.

-If you get an Aluminum block LS you can shave some weight off the front of the car, which is a bonus for handling.

-The improved architeture of the LS and LS control system means it will have better manners, more driveable, better fuel economy and better idle quality for a given power level.

-mating the ZF to an LS is not exactly straight forward, you need a quicktime bellhousing which then has to be modded, then you have to get creative on clutch hydralics, it doable but not easy. You could also sell your ZF and use the $$$ to by a New tremec T56 magnum F, which allows you to use 4th gen LS1 f-body bellhousing, clutch and hydralics. your call. On the other hand retaing the SBC presents no issues at all aside from perhaps a more stout clutch to handle the power.

-The original ECM in a 1990 is pretty obsolete, especially if you want to use it for a 500rwhp 383. Yes, you can have chips burned but it is going to be a pain. I've been there done that, your best bet is likely to get a more modern aftermarket ECM. Holley makes nice systems for SBC and LS applications.

One finaly thought, in my opinion an observation an LS swap gets more attention than a modded SBC at a car show (if that's your thing). But i'd say bang for the buck SBC wins. If budget is not a major concern then LS swap it!

 

A 383 SBC is going to have to be fairly radical and unstreetable to put an honest 500rwhp down without a power adder. The limitation is the head architecture: really awesome SBC race heads barely scratch the surface of what LS heads can do. The displacement is another limitation. You should at least consider a 396, and anything bigger (e.g. 434) will cost a good bit more money. So as an example, my 396 LT4 had heads that flowed very similar to AFR 195 Comps (the CNC'd ones). With a small cam it made around 415-420rwhp but was fairly nice on the street and could lay down 26mpg on a long highway trip. With a bigger cam it made 460rwhp, but you basically couldn't use 6th gear because it wouldn't pull it at 60mph. And there was a noticeable loss of power below 3000rpm, whereas with the small cam the car pulled hard right off idle. It really needed 3.73 or 4.11 gears to use that cam. Getting the next 40rwhp would have meant a really radical cam that would require even steep gears, and it would be even less happy driving around in traffic and such. Obviously a supercharger changes all of this! It kind of depends on how you want to use the car.

If you have the money to spend, 500rwph with an LS is trivial. If you look at Chris Ramey's C4 that just won the Optima finale, his LS puts 650rwhp down. That's a sleeved stock block displacing 468cid (I think?) and heads that flow like no SBC head could dream of. That's a known combination and places like Horsepower Research can do the same for you in a setup that will be reliable. It just takes money. It takes a lot less money to get 500rwhp, of course. And at that power level you can have good street manners and a nice, flat torque curve (again, you have to spend some money to get that last part). You still want displacement: I'd look at a 427 LS7 setup, at least. As DMITTZ points out, LS swaps aren't as simple as many people make them out to be. But they can be done. You have to figure out the dash displays, as well as the transmission setup.

All that said, 500rwph in a C4 is a shitload of power. I don't think most people who bench race realize how fast a car that really would be. My mild 396 allowed my 96 C4 to pull a stock C6 Z06 on a roll. In case anyone forgot (it's easy to do), that Z06 ran high 120s in the quarter mile. It was fast (505hp and 3100lbs will go fast). That puts my car probably ahead of a ZL1 and around tied with a Hellcat Redeye. A new GT500 would have pulled on it a bit, but a 2013 GT500 would not. Again, I was making around 420rwhp. So are you sure you need 500? Because one way or another it will cost you a lot more for the extra power.

 

That’s an understatement in my opinion. As you know, I just finished my LS swap (stock 6.0L mated to stock 700r4). I took BLK_BETTE to a car meet and parked next to another C4 with some relatively wild mods, nobody cared about that C4. I spent the entire night talking about the LS swap to every visitor.

While it does take some initial money to get the LS swapped in, you can get away with less. It really depends on what you want to maintain, and how deep your pockets run. I can tell you that my stock 6.0L lays you out. I mean, wow 😳 the grin I get knowing that it’s stock and it’s already ‘sit you back’ fast. If only I had more money for power adders and the breaks that come with it.

the way I would look at it, you get more reliability at the same money and power that you’d put into a built engine. But that’s my opinion and I never had a built C4.

 

Of course the other option is one of World Products blocks that use a SBC bottom end and a LS top end. Drops right in, uses the correct front of engine parts. Bolts right up to the transmission with NO modifications. Uses the SBC engine mounts.

Initial outlay is the block of course.

If I had the money and wanted a high HP C4, this would be the way to go. It is the best of both worlds and the bores are big enough for some impressive cubic inch numbers.

 

The world products block is a pretty neat product, especially if your wanting to reuse your transmission.

what accessory drive would you use with such an engine, the SBC of LS accessories?

 

Hello, I own a 1987 Chevy Corvette and I just rebuilt the engine on my car. I put a cold air intake and a dual exhaust system with out the catylast. The car runs cooler and quicker acceleration. My advice to you would be to keep it fuel injected because you get more horse power. A carburetor engine needs more modifications to achieve the same horse power as a fuel injection engine. I put a shift kit in the four speed automatic and it shifts very firm with out no loss in rpm.

 

I have found this on their site:

http://www.worldcastings.com/



interesting reads:

http://www.superchevy.com/how-to/pro...s-crate-engine

https://www.enginelabs.com/engine-te...-engine-block/

https://www.onallcylinders.com/2017/...-block-part-1/

https://www.onallcylinders.com/2017/...-block-part-2/

 

Well...that is a very interesting option! That dyno test result was...juicy.

 

With either being NA you're still going to need a pretty decent amount of cam to get to those levels. Difference being the LS will drive better HP for HP beyond a certain point and will not need super exotic heads to get there... probably can't do it stock heads but decent off the shelf heads should get there. The big difference is the rotating assembly in the LS can probably be left alone to do it... you'll need to work over a GEN 1 to spin it that hard safely. Work is involved with both... its just what kind you want. LS swap most of the work will be in the swap. GEN 1 will be mostly making the engine want to run and live at that... so its that callyou need to make. You will have a crap ton of room to grow with an LS if you boost down the line though. Just saying.

Is it an arbitrary HP goal you have or performance. Depending, you can probably do more with less... car is pretty light.

 

I like this too but it still uses the smaller diameter SBC cam core

 

Unfortunately you have to chase it down into the links/details to find that piece of info

https://billmitchellproducts.com/pro...on-w-ls-heads/

 

You can build to 500rw either way. 500 at the wheels is nutty in a C4, my 398 doesn’t put that down and it can get hairy enough at 500 crank HP.

But the LS will be tamer and easier to drive around because of the heads and the design geometry, to put it simply. You just have to take care of a lot of things mentioned above, tranny, computer and wiring for that.

Doing a Gen 1 SBC to 500rw NA takes a lot of cam, and she won’t have great manners from stoplight to stoplight. It would be more at the limit for the computer to handle and id treat it more like a track car as a result. I could probably put a SC in mine and get there and be tame enough to drive, but it is a big expense and I don’t want it.

 

Can be done either way. N/A will probably be more expensive than boost honestly. 500 at the wheels will be 600-650 at the flywheel depending on a few factors.
Cost will probably come out about even, depending on what you want out of the car.
Gen 1 will need a lot of major hardware replaced. LS will do it on 95% stock stuff, but then you'll have to actually do the swap which will cost $.

 

Like that world block, imagine a 4" stroke wtih some worked MAST heads and a solid roller?


Leave it EFI , throw some boost to it youll get there. tpi421vette and rklessdriver have done this many times

Few guys on here have 9, 10 second st C4s. TA has an 11 sec TPI car na car no power adders.
How much do you have to spend?

I have in my other car what youre looking for...will take 10 to get it though..80 miles...18k wrapped up in the build...youll run 10s easy
Excuse the plug.....(I want a big block)

 

I would really really like a built 427 BBC. A full rollerized, sequential FI 427 would be such a cool motor in a '90 or '91. When I was in my 20's (when I bought the '65 327) a guy in the crowd we ran with (my age, maybe a few older) had a '67 tri-power. Ever since then I have just wanted one. Unfortunately he put it into a tree and burnt it up effing around in the Cuyahoga Valley National Park on the road that goes to the Ledges. Even in a Vette that road was not the place to be doing 100 mph. He was lucky, he pulled his unconscious younger brother out of the burning car before it went all the way up,

Then modify the hood to look like a '66 BB hood. Had I the money to build this, the new analog dash I have would go in this car, not the '96.

I have a 454 in one of my pickups. It is a stump puller. I think the 427 just sounds better.

 

I don't understand the allure of a BBC in a C4 unless you're going to build it out to well over 500cid. You can literally build that World Products Motown block to 427cid with their conservative build, and throw good-flowing LS-based heads on it and make serious power in a package that actually fits easily into the C4. What's the point of adding 200lbs of extra BBC for no improvement in displacement?

 

For me probably an old guy thing just hanging on from days gone by. I truly realize that the World Products option is the very best way to go.

 

He's got a L98 so he's not limited to a 4" bore. I think that he should put a 4.125" bore in there and build from that. That solves the "tranny fitment" issue with the LS, and it gives him at least 400 CID to start with, economically.

 

they sound bad *** lol. In reality I agree. An all aluminum big block would be something though