Just accuqired an 1992 Corvette C4 the original engine was seized but it came with a replacement engine from a 1995 Chevy Caprice but I also have an 6.0 Vortec engine(complete with wiring and ECM) Ive been saving for no particular project, weighing my options as to which to go with. What do you guys think?

 

LSX requires more work to fit but has more potential

 

Well I plan on selling the car eventually(within a year or two possibly), I know nothing about the replacement engine(mileage, condition, etc) it does turn freely, and plenty clean under the valve covers, the 6.0 has 113k miles and ran great when pulled...I dont plan on making any performance mods to either. I am some what familar with LSx conversions as I have done 2 on older cars, but sure I'll run into something new attempting to do it on this C4

 

Do a search on here,
the swap has been well documented over the years with the pitfalls and solutions
Some very good threads with pics and discussion
Exp
http://forums.corvetteforum.com/c4-t...-progress.html

 

That threads' over 6 years old.. Lots of newer info out there for the search..

 

If you are planning to get rid of it in a year or two, I would get it running with as little cost and effort as possible. The Caprice LT1 should be a simple motor swap, while the 6.0 would be more difficult and probably cost more.

The Caprice LT1 are a little different from the Corvettes. The main differences are the cast iron heads, a milder cam, and a two bolt block. I have read that the cast iron heads flow a little bit better than the stock aluminum heads (not much though). Even stock the Caprice/Impala runs pretty good even with a lot more weight. My Impala and Caprices ran high 14's near stock. Although not near a corvette, that is pretty good for hauling 4200 pounds.

Depending on how bad the corvette motor is, you may be able to swap a few parts to the Caprice motor also, or depending on you budget, could upgrade a few parts (like cam, etc.) while it is out.

My thoughts are that the Caprice LT1 would be a better fit to the information you provided, unless you just want to do the 6.0 swap because you like projects.

Good luck with your choice and swap.

 

Unless you plan to keep the car, just use the LT1 motor. If your orig. alum. heads are good, I would swap over the top end of the vette motor along with the cam and all accessories. The only real difference in the 2 blocks is the vette was 4 bolt main vs the other being 2 bolt main. But again, plan on using all the orig. vette accessories, intake, manifolds, timing cover, opti, etc.

 

Well from amount of water I found inside the original corvette engine Im going to have to assume the original engine had a head gaskets and or a warped heads, I knew I would have to reuse the accessories as the replacement engine didn't come with any, I was wondering about the timing cover as I knew the 92' LT1 and 95' LT1 had different timing covers and opti's, not sure of the condition of the corvette cam.

 

I think the nose of the cam is different between the 2 cams

 

Is it neccecary to swap the cover and opti? I know the 95 has a vented opti but would that have a negative effect on anything?

 

[QUOTE=Atl_monte;1582179521]Is it neccecary to swap the cover and opti? I know the 95 has a vented opti but would that have a negative effect on anything?[/QUOTE]


Its been about 6-7 years since I did it, so double check with others

I think on the 92 you have to re-pin the connector that goes to the opti in order to use the newer version. I know on the 93 just had to get the short plug harness that goes from the opti to the car harness and it was plug and play. It was about 1 ft long. But the 92 is 5 pins vs 4. The one extra is a shielded ground.
BTW you still will need the short harness that plugs into the opti.

 

I don't know, it's really a tough call here.

I would think that a '92 with a Caprice motor w/ unknown mileage would bring a bottom dollar return on your time investment. Cheaper and easier to do, yes, but then selling would become a long process, with much haggering and tire kicking, and "I'll get back to ya". The potential buyer for this car would be a "project" seeker, that plans a building the LT1. As far as the opti, you can splice in an adapter to the harness and use the '95.

But I would think that a LSx Vortec swapped Vette would attract more attention. Though, I can't honestly comment on the work involved as I have not done nor researched the swap. I do know that they are pretty common and it's well documented, and that LSx engines are much better supported in the aftermarket sector. Of course if you did this, you just might change your mind about selling it.

 

Heres what I typically recommend:

L98 c4's go with an LSx if you are gonna do the trouble of engine swap.

LT1 c4's that already have the lt1, then mod the lt1. Aftermarket parts like AFR195cc comp ported 1039 eliminator heads will make your lt1 perform like an LSx.

However, be aware there is so much more available aftermarket for LSx.
I know I had to take a welding class at a local tech school so I could learn to make parts (custom supercharger brackets, etc.) for my LT1! Thats how bad the aftermarket support is for the c4 Lt1.

You are in a unique situation where you already have LSx 6.0.

Is this iron block or alum block? If its alum block use it. If its a heavy iron block, I wouldnt waste your time (with the LSx) unless you want to eventually turn it into a 1000+ rwhp forced induction screamer where the iron block would be more useful.

c4 is meant to be a lightweight sportscar (thats a big advantage we have vs. modern 'heavy' sportscars) and a lightweight alum block LSx will continue those goals. If road race is your goal, then keep it all lightweight.

If drag race is your purpose then, sure, you can off-set the extra 80lbs or so the iron LSx block weighs with insane HP.

Personally, an LTx (or SBC) making 800 rwhp excites me moreso than an LSx just because Ive seen it done so many times on the Lsx due to all the plug-n-play kits, tunes, etc. from A&A, ECS, etc.

To build an LTx requires intimate knowledge of tuning, heads, mechanics, etc (you just dont get a mail-order 800 rwhp LTx tune from somewhere).

 

I recently put a late model optispark and new cam into my 93's engine.

The 92-94 c4 optisparks have a little driveshaft coming out of the center of the cam that will drive the optispark

The 95-96 has an offset dowel pin coming out of the camshaft. The aftermarket cam I bought had this dowel pin coming out of it.

I looked at the stock cam and it does have a dowel pin coming out of it. However, it only extends .300" from the cam - which I dont think is enough ( I cant remember the exact length the dowel pin needs to be, but someone here would know.).

These dowel pins are typically press-fit (inside the cam housing) and can be either pounded in, or pulled out. Pulling the dowel pin requires an unbelievable amount of effort and Im not sure how easy it is to do. Ive heard of people (nathon plemons on here) found it easier to buy a new cam vs. try to pull out a dowel pin from the cam.

So it may or may not be possible to pull that dowel pin out from a stock cam from a 92-94.

Now, the electric harness is a lot easier. The electrical harness has an intermediate connector and you can buy the 95-96 optispark harness and it will connect up to the intermediate connector on a 92-94 engine harness. I think there was an off-set in the plastic housing of the intermediate connector that was different, but just a quick trim with an x-acto knife fixed that issue.

Last thing I want to mention is the optispark. Dont cheap out on this part. NOS or OEM is the only type to use. No MSD's, accel's, 'Summit' brand, $59 e-bay special, etc.

Im using a Delphi late model optispark ( i believe these were OE) and Im having great luck. I tried an AC Delco REMANUFACTURED optispark and the optical sensor (even though it was a genuine mitsubishi sensor) was defective. Car ran for 2 minutes then died.

 

If you have the money to buy a LSx engine, save more money buy buying a running C5 Corvette.

 

Not to mention few have managed to get *everything* working when doing a late C4 LSx swap. Seems that there is always something that doesn't work...cruise control, ABS, some of the digital display readouts, etc. The one swap I'm aware of that truly addressed everything was north of $20k to complete. Granted it was via a shop, but even if you do you're own work you'll have a minimum of $8k- $10k sunk into a $6k car that is now bastardized and difficult to sell. Of course mods never pay off when you sell, so you just have to decide how much disposable income you're willing to send along with it.

 

PLRX & 96GS#007

Yes a c5 or c6 is the easy way out.

a c4 is just that much harder (and more expensive), but it is possible.

Ask Aaron AKSRacing about is 900 rwhp c4 monster or this c4 that run's 8's on an IRS.

Id love to see this c4 pull up to a twin turbo c6z or a literbike for that matter.

http://www.youtube.com/watch?v=bpP20NFmk3c

 

No argument here. With enough time and money, the sky is the limit. It's simply a question of value. For some, dumping $20k+ into a $6k car is value from a fun and entertainment perspective. I don't ever want to know what my total was for my '96....hell, the last engine was $10k...so I've "been there, done that, got the t-shirt to prove it"....but it was a LOT of fun.

I just don't want the OP to think this is a quick/easy snap together mod. It's quite involved if the plan is to go "all in" and make everything functional.

 

Actually, as I understand it, the iron blocks are better for this swap in terms of suspension. While I don't have the exact numbers, and don't really care to spend time looking them up, the iron block Lsx and the iron block Ltx motors are closer in weight. The Aluminum blocks require suspension mods due to lighter weight. Granted, if I were doing the swap, I would think the suspension work would be well worth it.

Though the goal of according to Al Monte is to be able to turn the car for sale. I still hold the opinion that the Lsx swap would make more sense and would draw a higher price for the investment. If it were me buying the car, and it had the 245 hp Caprice motor w/ unknown miles and condition, I would need a fairly cheap price to get motivated. Might as well just sell it as a roller, and give the motor just to clear space in the garage if you ask me. But, if it had, even a stock LSx in good condition, there would be a more motivated buyer out there.

 

He already owns both the motor and the car. But otherwise, yes, getting the C5 would be the better way to go.