makenzie71

I've seen several rear turbo builds and even have built one...but I'm not sure if it counts since the engine was back there too. Seems like there wouldn't be any shortage of room under the hood, though. I guess the real priority on getting started here is finding the wagon. Seems they're a bit thin...

Phoenix'97

I wouldn't give up hope. You may not find one on the internet. While out on delivery I have seen roadside LT1 B and D body cars for sale. There has to be someone out there selling one and the body is not in totally banged up shape. I do understand, there is a cult who absolutely love the caprice/impala and for those interested in eco-modding, the wagon shape is enough to improve upon to get incredible gas mileage with the right modifications.

With regards to the rear mount turbo, I just wanted to throw it out there if you were unaware of them but you are. I think the set-up is very neat despite the additional plumbing and how to place the new air cleaner. This is only if I won't be happy with the naturally aspirated set-up depending upon what I choose by then.

94TAisfast

I know it's possible and not really any trouble on the stock engine. I'm just playing the devil's advocate. I've had some mail order tunes that were a lot more trouble than they were worth, and would have much rather gone for a dyno tune instead.
As for making 350+ at the tire, you have to remember that the 5.3's are pushing a 4l80e, through a heavy duty 4wd system, with gigantic wheels and tires. A decent tune through a 4l60 and a 10 bolt with all the bolt ons should get right to 350-370. If we're talking a 6.0, then really it's just a tune and headers away from 400 at the tire. Not to mention the fact that the LT1 is a dying breed, and if OP keeps the car for 5+ years, replacement parts will be harder to come by than they already are.

Basically, it's more work, but you get more reliability, more economy, and more power for the same money if you go LS(assuming OP wants to be closer to 400whp than 350).

BALLSS

a "mild" cam in a LT1 383 with all the supporting mods can make 390-400 rwhp all day long and be a DD and pass smog and have a very mild idle....with a mail order tune from the right person

Phoenix'97

I understand this point of view but I would not want to discourage makenzie71 from this project. Yeah, parts may be harder to come by for the second-gen 5.7L LT1 but aftermarket sources exist for certain parts if you search hard enough. Also, I understand, the LS family of engine is superior when it comes to breathing the design of the heads and overall power production, a lighter all aluminum engine block, the distributor-less ignition system, and the PCM. Many people opt to swap over to the LS engine yet, in my case and for argument sake, I prefer my LT and I am sure makenzie71 prefers his as well. It is always cheaper to work on a factory engine that your car came with! I know the engine, I accept what it lacks compared to the LS engine yet I also see the benefits behind it's reverse flow cooling set-up and cam driven water pump compared to the belt driven LS water pump. I also see the benefit in my LT1 being a small block chevy engine which paves the way for my desire to modify and fit a factory TPI intake on my LT1 and really tailor the engine for lower end and mid-range torque production. Even when considering turbocharging this set-up, it gives me big block torque potential in the right RPM range while helping me to maintain EPA rated fuel mileage. I don't want to hijack makenzie71's thread but lets just say there is still room to improve our LT1s in the way we deem fit with our tastes and wants out of the engine. Discouraging such builds and pushing LS engines really kills the creativity to be had...

383z

iTrader: (2)

OP, if you can find someone to tune it, then build it. You will be able to find all the parts you need down the road. All you need is a cam, good exhaust, air intake, and tune.

If you can't find a good tunner go with a 5.3 with a 4L80-E. Cam, exhaust, air intake, and tune. Stock 5.3's with 4L80Es pull boats and campers everyday in trucks.

hokeplaya05

iTrader: (3)

for the record, 5.3's never had a 4l80e behind them since they were only offered in half ton trucks/SUVs, so they had 4l60e/10 bolts behind them as well. an ls swap/build will cost twice what it would cost to get a 350whp lt1, heads/cam package is ~$1500 and a mail order tune is $200, done. I've never had an issue getting replacement or aftermarket parts for my lt1 either, i can go to any local parts store and get any gasket or hard part to completely rebuild one without issue. all i am saying is i don't think it makes sense in the OP's situation to swap to an LS for what his goals are with the car. they are easily achievable with the current lt1

Fast355

GM did put the 4L80E behind the 4.8 and used a 10.5" full float 14-bolt with 4.10 gears behind them and despite 305 HP rating are GUTLESS. The 4.8 and 5.3 are basically the same thing to me. Different crank, rods and pistons, but otherwise identical. They share the same block, heads, intake, exhaust, camshaft, etc. Just stroke, rod length, and the 4.8 has flat tops to maintain its compression.

I too would personally would stick with the LT1 setup. 350 WHP LT1 will run ALOT stronger than a 350 WHP 5.3.

There is a reason my Express van I tow with has a Vortec 350 still in it rather than the 6.0L I have on the engine stand. That reason is called TORQUE.

Phoenix'97

makenzie71,
How is your search going? I just did a google search out of curiosity and yes, there are a few Caprice Wagons from 1991 to 1996 up for sale on various auto sales websites. Their condition, naturally, requires on-site inspection. I did see one with relatively low mileage.

94TAisfast

My comment about parts availability is based on looking ahead. Right now, it's not that hard to find parts for one. However, 10 years ago, it wasn't that difficult to find parts for a car such as a 1995 Subaru Legacy. Now, It's pretty hard to find stuff. If OP is getting this car for the long term, LT1 parts like water pumps, gaskets, ignition parts, and so on will be a bit harder to simply go to a parts store to pick up for a quick repair. LS engines have become what the 350 was in the 90's, so they won't be dying out anytime soon. It's up to OP what he wants to do, but I was mostly looking at issues I've encountered while working on my car.
Wait a second, aren't you the guy who wanted to turn an LT1 into an L98 or an L31 to make more torque because you think LS engines are a lie and the 350 was God's gift to mankind?

97Z28SS

iTrader: (5)

Something I haven't seen anyone who's advocating an LS swap mention is the PCM and wiring harness changes required in order to get the LS swap working. That adds to the cost of a swap as well.

hokeplaya05

iTrader: (3)

fair enough, although I don't believe that will be the case. you can still get all that stuff for sbc's and they haven't been in production for over 20 years, I think as long as people are fixing up and modding lt1's there will be those type of parts available.

you are thinking of the poster right above you, phoenix97

I thought I mentioned that but I guess not, but good point. ls swaps can certainly be done for cheap, but not as cheap as it would be to get 350 reliable hp out of an lt1.

94TAisfast

However, the Gen I was in production for around 50 years, and millions of them were made. There weren't all that many LT1's made(by comparison, and hell most guys don't even know what the heck it is), but I still stand by what I said about just going down the block to the store to get a fresh opti if yours takes a dump. You'll always have internet availability, but in ten years time, I'm 95% positive you will have a much harder time finding parts at your local Autozone.


Ahh, yes. I glanced over that thread and Fast was the guy who brought up marine engines.


And usually you can get a decent harness with a pullout, if not dirt cheap on CL or eBay. My thought process with this is more along the lines of "build it now, keep it forever" and I would probably go with something like an LS swap for that. A turbo LT1 would be fun, but for economy, power, longevity, reliability, and parts replacement, I think an LS is the way to go. Just my opinion, and I know it's not a common one.

Fast355

If I had a LT1 it would not have an optispark. My L31 has the EFI Connection 24x kit and D585 coils on it being run by a Gen3 PCM. Parts for the L31 are still common as dirt on the internet and honestly the LT1 is not far behind in availability. I can order parts on RockAuto and have them in a day if needed anywhere in the country. Parts builders still make stuff for uncommon 30s-50s engines so getting those parts likely will not be an issue for years to come. Hundreds of thousands of LT1s were built and many are still on the road.

If I were doing a LS build it would be a later 24x base 6.0L with gen 4 rotating assembly, rectangle port 6.2 heads, a small cam for good driveability and a LSA blower on top. Fuel mileage could still be decent if you keep your foot out of it. When I finally kill the L31 that is what will end up in my Express van. But having the 8.1 Tahoe for a daily driver I see the 5.7 living a good long time.

Phoenix'97

This is merely an assumption on your part. Yes, with time, it is foreseeable that parts will start to become discontinued, even remanufactured parts. However, a way around the water pump problem would be to use an electric conversion come a day when they stop remanufacturing our LT1 pump but we could be talking decades from now. As far as the ignition, we have the 24XX conversion and a kit exists where you can use an LT1 harness to plug into an LS1 PCM that was modified for LT1 connectors. There exists plenty of aftermarket parts and companies for LT1s so I wouldn't give up hope!

The only saving grace is having custom shops and a demand to keep older muscle cars alive despite the cars of the 80s and 90s not having the same lure as those metal body cars of the 30s/40s/50s/60s/70s. There are ways to keep the second-gen LT1 engines running, and if desperate enough, it may require the same ingenuity that Cubans have to keep old cars running and looking good.

Oh boy, now we must try to discredit my efforts by bringing this up. To correct your statement, I NEVER PUT DOWN LS engines NOR STATED that Chevy 350s were "God's gift to mankind". With regards to engine modification I want to do, I want to have a machine shop modify a stock TPI INTAKE base to fit to my LT1 heads. I may even be able to use my LT1 fuel rails on the TPI base with some minor adjustments. The goal here is to shift the LT1 torque curve over to better suit my driving style and performance goals. I don't care for high RPM torque performance when I can't use it for my daily drive. The only real joy I get to have is green light acceleration up to 5000 RPM which is where the TPI intake is tuned for it's torque production. So, short and sweet, I want the most torque production from a cam working with the TPI intake on my LT1 from off idle to up to 5000 RPM. An LS swap is out of the question after I researched and discovered how much it would cost even if I could find a donor car because I can't do the swap myself! Cha-ching for the shops that I need to pay for this service! Besides, I won't be happy with an LS1 because I am still running into the problem of how to modify it to suit my desire for lower and mid-range torque. My LT1 with a TPI intake best fits the bill. Yes, I am making the car slower with a lower horsepower rating but for daily driving, at least I will be using all that low end to mid-range torque that this set-up will give me, unlike with what I am doing now and certainly unlike an LS1 if I were to have one swapped in. No one has an LT1 with a TPI intake and probably no one will ever do it, so I might as well relish in being the first!

Now I feel like I just hijacked the thread...

sbs

iTrader: (1)

There were a ton more LT1s built than a lot of older engines that I can walk into Autozone and get parts for.

Most of the LT1 is common with the Gen I which is never going away.

LT1-unique bits that get discontinued elsewhere will be reproduced by the Corvette suppliers, they'll just cost more.

Maybe in 30 years you'll have to switch to the Y-body water pump configuration after the B-body supply dries up.

Fast355

You are definately not the first. I know a guy that put a F-car LT1 with TPI on it in a Vortec truck using the Vortec truck PCM and rear mounted distributor.

SS RRR

iTrader: (2)

Phoenix'97

Well, I would love to communicate with this guy to find out how that set-up was for him and how best to go about it on my car.
Trying to maintain factory EPA fuel rating out of a mild cam is unrealistic?! I never said I was going run the car no higher than 2000 RPM! When I drive conservatively I prefer to have the car RPMs below 2000 since I don't need that much torque to get the car moving, although sometimes I have no choice when going up rather minor inclines. This is what started my search for how to give my car the torque levels in it's factory stock format at 3000 RPM down to 2000 RPM or preferably 1500 RPM with the proper cam. Everything else is just for "fun" and more acceleration from a green light without using higher gear ratios.

Now, if you can swear to me that the LPE cam you suggested will help me achieve near stock mileage when conservatively driven and the low end and mid-range torque I seek out of a stock emissions compliant exhaust set-up, unported heads, and the TPI intake I desire, then I will suggest it to the engine builder I choose to work on my LT1. With regards to further improving my fuel mileage in the city, some eco-modding guys guided me to a conversion using the GM BAS Belt-Alternator Starter enabling instant start-stop while helping to remove the traditional and "inefficient" alternator and starter.

I digress...