When i'm going to go see the Caprice i'm going to take my endoscope camera to look inside the cilinders and will also be measuring the compression.

 

First and foremost welcome to the site. How's the weather over there? It was -15 F this morning in Minnesota.

To answer a few questions you have:

The Opti Spark can be a weak link but overall I think it gets alot of negative flack that's not always true. Some people go 100,000 miles and never have an issue. I haven't been so lucky. I've gone through one China, one Delco, and one Delphi in 30,000 miles. Knock on wood the Delphi has been on there the longest. I would like to think its been more bad luck than anything. The China one I got what I paid for. The Delco the Rotor fell off so it might be fine otherwise. I kept it as a spare in case the Delphi goes bad.

With a good free flowing intake, long tube headers, a performance exhaust, and a performance computer tune you'll be close to 300 at the tires. Add a cam to that and you'll be over 300 no problem.

I wouldn't call it the most unusual swap but with all the LS engines now its not the most common by any means anymore.

If I were you I wouldn't do a cam but do all of the above before that and see how you like it. The V8 is going to make alot more torque than the 4 cylinder your currently used to so keep that in mind as well.

 

Thanks for replying Nick

Well winter has just begun over here but it's all still relatively normal, 0° celcius = 32° F

After looking at this video (https://www.youtube.com/watch?v=azPKIjxmmdU) and finding this article (1996 Chevy Caprice Performance Upgrades - Super Chevy Magazine) i think i might just forget about the headers.
Also from first hand experience i have put my car on the dyno with modified headers then 5 months later back to standard and there was no difference to be seen in the figures.

Got some more info regarding the caprice i'm going to check out on thursday, first owner car and has about 65 000 miles on the clock. It's sitting at a local carshop who has been looking out for a good V8 for me since i spoke about it. He has serviced the car regularly and says it's got good compression.

An LS-engine is not an option, they are quite rare over here and will cost about 4500 dollars for the engine. And honestly i'm not that keen on buying a dismantled engine which i know nothing about. Plus they can lie about it all they want, by the time i've got it running and something were not to be ok then were a few years down the road. So getting a running car for cheap is my plan.

 

Ow yea, if i focus only on these basic mods would i also need to focus on reprogramming the ecu?

 

A cam will require PCM Reprogramming and better (higher lift) valve springs. For a 300HP LT1 in a light weight car, I'd look into the LT4 Hot cam or the Comp Cams-502 cam (Comp Cams #07-502-8). These cams are very similar, easy to tune, and should get you to 300HP even with stock heads.

The Caprice LT1 will have iron heads, which are fine....but they're about 50 LBs (22-23 kilos) heavier than a set of aluminum heads. The aluminum heads are good for a bit more compression than the iron heads, but in the car you're racing, going to aluminum heads for weight savings alone, may be an option.

I would also look into getting some 1.6 ratio roller rockers. Just be sure that they are for heads with center-bolt valve covers!

Valve springs? Just make sure that you get springs specific to iron heads or aluminum heads....whichever you decide to go with. Also, be sure that the springs you go with are good to at LEAST .550" lift.....I would go with .600" springs, myself.

Best of luck!

KW

 

From experience long tube headers will wake an LT1 up quite a bit. Shorty headers have proven to be almost worthless at best. The stock LT1 manifolds actually flow pretty good in fact just as good as a shorty header in my opinion. So like I said before I think I would just get the engine swapped over and running and see what you think at that point. Its gonna feel like a power house compared to what you have now. So in theory no you won't need a custom tune however a custom tune wakes these engines right up as well. So maybe that's something you can do down the road if you decide to put a bigger cam in it and add long tube headers. 65,000 miles on that Caprice is nothing, I've seen some caprices with over 200,000 miles and still going down the road.

Also I was curious as to what car this is all going into. Some pictures are always welcome as well.

 

it's going into this car - i've seen this swap online a couple of times

 

That's a sexy car if I do say so myself. I'm anxious to see the end result to say the least!

 

Just went to have a look and drive with the car - i think i'm having this, nothing really which stood out. Compression is +-10 bar on all cylinders.

 

I'd say go for it. That thing is clean as can be and being that it was a hearse I'm sure it's never been beat on. I don't think your gonna find anything nicer than that.

 

McLaren...

While the LT1 is basically the red headed step child of small block Chevy's, many do get transplanted in various cars with some even carb conversions.

The donor motor you are considering is the iron head version which makes 260 flywheel HP. To get 300 "rear wheel" HP would not take much. A cam like the LT4 hot cam or Comp 502 will work well with the stock heads with the exception that you will need new valve springs. Roller rockers vs. the stamped rockers on the car would also be recommended. 1:6 ratio

with the cam, spring, RR AND PCM tune you will see 300+ RWHP using stock exhaust manifolds. injectors and throttle body. A mail order tune should be fine as I suspect finding a dyno with a qualified LT1 tuner over there is unlikely

The Crane 10309-1 spring lit is a direct drop in replacement spring. While I have never used them, Alex springs have good reports

VALVE SPRING KIT, SB CHEVY VORTEC, HI-PERF HYD ROLLER - Alex's Parts Sales

 

And where could i get my hands on a mail order PCM tune?

For example these guys seem to have a page where you can put all of the data of the engine: PCM for Less

But perhaps there are established names out there that you could point out...

 

That is one source to use for mail order.

Sounds like you are using a manual transmission. Typically the speedometer and tachometer is controlled by the PCM. Your 944 transmission may be a challenge but certainly correspond with the tuner on how that can be accommodated unless you already have a handle on that

I have always used Ed Wright at Fastchip. I think he still does mail order tunes. He typically is not the cheapest but he is considered very knowledgeable. He was one of the original tuners when these platforms were new and has been a drag racer most of his life. He sold his dyno shop but I believe still does mail order.

Pull the PCM from the donor car and the wiring harness. Likely for your application several things (mostly emissions) will be tuned out. No doubt you will have to modify your existing wiring with the donor engine harness

www.fastchip.com

You can also do a search on this or other LT1 forums on other tuners. Solomon is one I have heard of but have no direct experience with