sgtskid

Fair Warning - This is going to be long But, hopefully it helps someone else in the future. (myself included)

Alrighty, I have had a plan for 12 years and now with the price of LSX's coming down my plans have been put into question. I am in information overload and I need some help.

My dream car has always been a Corvette. Ever since I was 4 years old and rode in a neighbors 78 Pace Car, I was hooked. I saved for a long time and at 18 I purchased a 1990 Quasar Blue Vette. Two owners, auto, 56k miles. All mine

From the beginning I've had plans of converting it to a 6 speed and building a 383. I've collected parts for the last 12yrs and have acquired a lot of stuff for the build. I want to have all the major components beforehand so can I tear the car apart and put it back together in short order. I refuse to have a car sitting on jack stands that I'm telling my grand kids, "i'm going to finish it one day."
Plus I still drive the crap out of it on weekends.

With all that being said, I need help/advice on which path to go down from people considering similar builds or who have completed similar builds.

Goals:
1. 400 RWHP
2. Manual trans
3. Trackable (road course not drag)
4. Pump gas
5. Streetable
6. Reliable as a 1980 Mercedes Diesel
7. Ease of conversion (see definition below)
8. Factory look
9. Use of factory gauges (if at all possible)
10. Creature comforts (AC, Cruise, PS)
11. Naturally Aspirated

Parts I have collected:
1. ZF6 with all parts needed for swap, pedals, slave, shifter, bellhousing, dual mass, drive shaft, c-beam -etc
2. D44 complete rotor to rotor with 3.75s? (been a while since i've looked at it
3. 1.75" runners
4. 52mm TB
5. Edelbrock intake base
6. Various other Misc parts and pieces good for engine build

Two Components remain:
1. Suspension
For suspension I was debating between going with coil overs or VB&P. after reading around and hearing stories about clearance issues with sway bars and coil overs, I have decided on the VB&P
http://www.ecklerscorvette.com/corve...1985-1996.html
http://www.vbandp.com/auto-parts.htm...category_id=58

2. Engine -LSX or 383? <--- where I need the help


Ease of Installation: I am all for a month of hard work but what I don't want is purchasing parts only to have them machined because they don't fit or have to do custom wiring only to find out I lose cruise or gauges. I would like as "bolt" in as possible.

Now the questions:
1. Build 383 and throw the ZF6 behind it
Pros - Bolt in, no custom work needed, retain factory wiring and gauges and creature comforts
Cons - ~$7k for engine (having it built), Difficult to tune, Could go with EFI system but added cost, still uses C4's notorious bad wiring, no diagnostics (OBDII), Engine heavily built to achieve 400rwhp
2. Convert to LSX and throw the ZF6 behind it
Pros - 400 hp easily attainable, reliable, lighter, easily tuneable, diagnostics, could sell original motor for $$
Cons - Custom wiring needed, LSX adaption to ZF6 questionable, retention of AC and cruise questionable.
3. Convert to LSX and throw a TKO500/600 behind it
Pros - ?
Cons - Finding a TKO with offset tail housing for proper shifter placement and with correct bolt holes for C-Beam.



I estimate that either the 383 or the LSX conversion will cost about the same amount (Before counting $$ recouped from selling parts). I have researched the crap out of LSX conversions and have found several threads with completed conversions but only a few with a zf6 behind them. Most were racecars with custom gauges and no AC and appearance wasn't an issue. Other threads had a shop perform the swap and details were lost.

I know VetteAid makes custom wiring harnesses but, how plug and play is it and does it work with the OEM gauges? Does it replace the LS harness?

Will I need the LS harness or just the ECU?

Motor Mounts - VetteAid has "bolt in" motor mounts and headers that require no cutting.

Which LSX is easiest to convert over, F-body or Vette?

What fuel pump is needed? Will OEM work?


C5 accessories are needed but I've read different things about the oil pans - Which one f-body or vette?

THE BIGGY - has anyone figured out how to mate the ZF6 to the LS? Quick time makes a bell housing but from one thread it needed machining. ZFDoc was working on adapter plates but I haven't seen or found any further information about availability or fitment.

I want to hear other peoples stories, good/bad. Advice. Things to consider...

References:
https://www.corvetteforum.com/forums...arts-list.html
http://vettaid.com/LSxPackagesKits.aspx
http://www.hotrod.com/cars/project-v...-project-cars/
http://www.zfdoc.com/projects.htm
http://www.superchevy.com/how-to/cor...remec-tko.html
http://www.superchevy.com/how-to/vem...4orce-wrap-up/

aDigitalPhantom

I doubt you can use the GM bellhousing for the ZF with an LS, but you can use a QuickTime RM-6039. (Quicktime lists it out of stock I hope they have not stopped making it) For me the bell housing needed coating removed one spot to attach to the trans. I am using the clutch and flywheel for a newer LS vette.

I am using the f-body oil pan.
The fuel pump is EP-381.

I cant answer on the vettaid harness they refused to sell me one so I made my own.

Polo Vert

Goal #8....Factory look. That right there tells you to go with a 383....problem solved!! Or better yet, sell all the stuff you have accumulated and buy a ZR1.

Paul Workman

Yep, true enough. Faced with the same quest, the ZR-1 was my choice too.

But, even with an LT5, some top-end porting, including bumping the TB from 58 to 63mm is going to be required, along with LT headers and free flowing exhausts, aluminum flywheel, and some dyno time to get the LT5 to 400 rwhp (naturally aspirated). The good news is the stock cams will easily make the power, but they will have to be phased to optimize performance. Not cheap either. But! You'll have your smooth (stock) idle, full use of the AC and gauges, and rock solid reliability.

(see 508HP LT5 YouTube to see how streetable the LT5 is making over 430 hp to the wheels...stock cams and all.)

Real killer-sleeper!

aDigitalPhantom

Something tells me that if the OP wanted a ZR1 none of the parts that have been collected would be. One of the reasons I did my LS swap, and why I don't want a ZR1 is parts availability in the future. I see SBC parts becoming less readily available, and I would doubt LT5 parts are common now.

sgtskid

Why wouldn't they sell you a harness? Did you keep the factory gauges or ditch them for an autometer setup? Did you need the LS harness at all?

I should probably clarify. By factory look - I want the whole package to look as though it rolled off the factory floor assembled as one. Not necessarily looking like the TPI.

I could also buy a C5 considering they can be found for $10-20k (or cheaper) depending on mileage and details. But why? I enjoy building cars and if i did buy a c5 I wouldn't be able to leave it alone either -extra money on top of the money already spent. ZR1's are getting harder and harder to come by and IMO - have a lot of one off parts that make them expensive to maintain.

At the end of the day, if I were to sell all the parts I wouldn't come close to the cost of a ZR1. I am not selling my car and I don't need another car...although i always want them... so I have chosen to rebuild mine.

86C4Z51

Good luck with your project. I plan to follow it with interest, not because I want to do the same thing, but it sounds like you're going to have a real challenge and have fun!

aDigitalPhantom

The factory dash is in use, and the only things that are not working right now are the fuel information (avg range, and instant mpg. I also understand these will not work without the factory ECM/PCM) and oil temperature. The oil temp is not working because I have not reinstalled one or wired it in yet.

the only parts of the junkyard cut LS harness I reused were the connectors, coil harnesses, and the wire that was long enough on a few of the connectors. The rest of the wire is new, and so are most of the sensors.

The speedometer, and tach were adjusted in the tune to read correctly.

pologreen1

You waited 12 years, you should know by now. Unless going boosted I don;t see the need for LS. If you think a 383 is good enough I'd just stay Gen1 and more cubes.

LinkandCuff

should he consider swapping in a 96 lt4 engine and adding a heads cam package. It would be really easy to swap plus all factory parts could be used and with a nice heads cam package and supporting mods you could be really close to 400RWHP with a stock bottom end.

aDigitalPhantom

I understand Mustang Dynos read low to start with. The owner of this says it reads even lower still, and is closer to 33% loss for the numbers it shows. I don't know what it really is so you can take what you want from this.

This is after I gave in and had it dyno tuned.

sgtskid

I've waited 12 years partly because life likes to interrupt. Trying to finish college, moving for work, getting married...wife in school and trying to pay her loans off....yada yada...excuses excuses. I am currently trying to put together an honest cost sheet comparing the two options.

If I go with a 383, I would most likely go with Golen Engine Services in NH. I have a quote from them to build one for me using my original block. My concern is getting it tuned. Golen recommends the Holley EFI system which learns as it goes but, that's another $2k.


If I go with an LSx, I'll try to buy a wrecked car and yank the drive train. MAYBE swap heads and cam and then drop it in. Tuning would be relatively simple.

When I started putting the plan together LS1s were just on the market and were still very expensive. Now 10+years later and they are a dime a dozen.


Swapping an LT4 and using the optispark would require a harness and ecu change out. Correct? If I'm swapping all the wiring might as well go LS.


Any work done to it or is it stock? Pics?

Mustang Dyno's typically read lower than others because they are a loaded dyno as compared to DynoJet's which are not. I believe both companies now have both options. I worked for a shop that had a Mustang dyno and customers would always complain because they weren't getting the HP they got at the last shop. Here is a great article that explains the difference.

http://www.badasscars.com/index.cfm/...prod/prd64.htm

dbgoodwin

I don't spend much time here in c4 land, but personally I would opt for an ls1 out of an f-body. minor work like ls6 intake, 243 heads, and a decent cam along with bolt-ons would easily have you at your goal without sacrificing reliability or drivability. It would also be CHEAP as people are always selling factory heads/intake when they do more radical builds. Also the LS is lighter, so for road courses you would have less weight over the nose of the car. Your car looks great, and if youre happy with it I would ignore everyone telling you to sell.

86C4Z51

DB you're welcome to hang around with us C4 folks as much as you like

drive it

Keep in mind the tuning part-you did touch on it. If you swap cam/head on an LS it's going to get involved as is a 383. If you don't have a good tuner nearby for hands on dyno tuning then be prepared to learn the diy tuning or you're apt to be disappointed/frustrated.
If you go with the 383-dump the tpi and find a super ram intake if not a mini ram.

touyech2883

What not just get some afr/equivalent heads/cam and a mini ram for it. That's over 400 hp at the wheels and no machine work necessary. Swap the zf6 and go LS hunting. it would be alot cheaper and probably less headaches. If you have LS swap money you can do alot with that gen 1 alot easier.

dbgoodwin

Wooo I have friends!

aDigitalPhantom

The engine was rebuilt. Most people say it has a small cam, but it is a CompCams 54-408-11. When I got the engine it was a 4.8L sold as a 5.3. I bought a used 5.3 crank from the machine shop. It got flat-top pistons, and Eagle rods. Currently it has the truck 862 cylinder heads new locators, springs, seals, locks, and retainers. LS1 intake, intake C5 accessories, and 98-02 F-Body oil pan.

I have only taken one picture of this because I don't like taking pictures. There is a lot unfinished in this picture.


My The confusion on the graph is caused by what the shop said. I already had that page bookmarked.

sgtskid

~200 lbs is quite a bit but, given that I am not a pro driver I wonder if I would ever notice.

LSx can be tuned through the OBDII and there are a few shops nearby that I have contacts with.

383 will need to be tuned through a chip and will require someone special to burn, dyno, adjust, burn, dyno.... Any future changes require the same process.


Have you built one?

Chevy Owner - did you use the quick time bell housing?


Thanks everyone for the comments.

aDigitalPhantom

Yes I did. I also made a bracket for a slave cylinder to use a clutch fork, and throwout bearing with the needed push type clutch.