I am looking for help installing a 94 LT-1 and Richmond 6 speed into my 71 Corvette. I need to find the correct motor mounts and any other items needed to install this engine.

Thanks,
Steve

 

Wouldnt you just use your c3 motor mounts? I think the biggest challenge with the swap is the trans and the wiring. Go to www.corvettefaq.com and look around under the conversion section and also the trans section. Should be a few sites such as this one
http://www.vetteworksonline.com/LT1%20conversion.htm

 

The C3 mounts will work. The LT1s still have the correct bosses for them. You will have to use C4 accessory brackets or some type of aftermarket ones.

 

Several companies offer wiring for this. Street and Performance, Howell, even Painless. I think the hardest part is locating the MAF sensor. Go for it, it will be fun. I have TPI in mine, and I love it.

 

Macguy, if you are running into problems try posting pics here. Im sure someone here could help you out.

 

Get it right! the late model motor is a LT1 the early motor is a LT-1 don't confuse the 2. One sets off car alarms while driving down the street, the other gets good fuel mileage, one revs to 7,000RPM, the other dies off at about 5,800RPM, one is SOLID the other is juiced for a cam.

 

I'm a '71 L-48 owner and posts like this always catch my attention. I can't offer any help for macguy03, but I am curious just what separates the base motor from the high reving high hp variant for the year 1971. Is it simply the cam and heads? Why bother with a newer engine if mods will get you close? Not the same, I know. And yet I still wonder.

 

70-78 LT-1/L-82 compared to L-48: L-48 is standard 350 Chevy 4bbl found in trucks, Impalas, and Monte Carlos. The LT-1/L-82 had: forged tuftridded crankshaft, HD "pink rods", TRW forged pistons, 2.02/1.60 valves, screw in rocker studs, guide plates, heat treated rocker arms, special cam&lifters. The LT-1 also had the hi-rise intake with the Holley 4bbl requiring a "big block" style hood. LT-1/L-82 will rev reliably to 7,000RPM and withstand detonation far better than any standard 350 checy with it's forged pistons. For 71 and later LT-1/L-82s a swap to earlier small chamber cylinder heads will reallly wake these motors up to the tune of about 25-40HP. LT-1/L-82 Vettes also had cast aluminum valve covers along with the simular 350HP-350 of 1969-70 (later L-82s after about 1977 had magnesium valve covers painted black by Chevy.)

 

Ahhh but here is the thing. The base LT1 intake manifold has runners optimized for 8500 rpm like a victor Jr. Some attention to the bottom end, and a new cam and a computer and you could have a real screamer.

If I was gonna build a TCC racing vette it would be an LT1 C4 Z51 with a manual.

 

Steve,

Do you own the 94 LT1 engine now?

Both c3 and c4 versions of the LT1 are excellent motors. I have many miles with both. The primary weakness to the c4 version is the “Opti Spark” ignition system. I rebuilt the one on my daughters '95 and it has been running great so far. The motor pulls strong to about 6000. The c4 LT1 was the first real Vette engine to come along in almost 20 years. The engines in between were a real disappointment to me.

The C4 LT1 gets about 28-30 mpg's on the highway. A c3 factory LT1 will get you approx to 25 mpg's with an overall gear ratio of around 2.5:1 is you use the Richmond 6 speed, a gear box I greatly enjoyed.

For the hassle you go through to hook up a computer interface for the c4 LT1, you can have a very streetable and even more powerful c3 LT1.

Most guys running carb'd engines don't really have them set up very well and think that the only way to get good mileage is to use modern fuely setups. Modern engines are truly a technological marvel as my '02 ZO6 has shown me. But I made as much power with my tweaked small block in my 69 and still got 20 mpg with a 3.36:1 rear and Muncie speed. My later ROD would have easily brought about 25 mpg's. the idle isn't as smooth, the emissions will be a bit higher; but 7000+ rpms along with a sound that means business would make an easy decision.

If my daughter ever wanted more than the 300 net hp that her LT1 offers, 400 net hp wouldn't be hard to build either. It would still be streetable too. I would not consider a c3 engine for her car.

The choice really comes down to two points:

1) Do you want to keep the same look to the engine compartment using similar pieces that are found in a C3?

2) Do you prefer computers and sensors over springs and diaphragms for engine management?

There are good points and drawbacks for either option.

Chuck

 

You didn't like the Tuned Ports? I love mine. It was a major improvement over the 81 carbed 350. We won't talk about Cross-Fire, but it was a big jump over 81 as well.

The fuel injection setups are much nicer to start in winter time. Depends on where you are in the country of course, but it gets cold where I am in dead of winter. I don't go out when the salt is out, but I do drive some on a nice clear cold day. You can go either way. There are pros and cons to each I agree.

 

Stick with a Corvette LT1. It will make the installation easier.
Dan
www.vetteworksonline.com

 

Markdtn,

No, I didn't really care that much for the tuned port motor. I had a '85 Z51 that I really did love for its suspension, but the engine was the same as a 1970 Nove 350 2 barrel. Same compression, same cam, same little valves, etc. The tuned ports looked racy, but the engine was all done by about 5000 rpm. This made for a great truck motor, but was not my idea of a Vette engine.

The first week I took delivery from the dealer, I changed to a L46/L82 cam and installed 2.02" slant plug heads with 64cc chambers. This upped the compression to a little over 10:1 and gave me much more power with a shift point a little over 5600rpm. Engine probably made around 300 net hp. This was ok, but not as good a combination as the C4 LT1 that came out later.

Chuck

 

Markdtn,

No, I didn't really care that much for the tuned port motor. I had a '85 Z51 that I really did love for its suspension, but the engine was the same as a 1970 Nove 350 2 barrel. Same low compression, same no lift cam, same little valves, etc. The tuned ports looked racy, but the engine was all done by about 5000 rpm. This made for a great truck motor, but was not my idea of a Vette engine.

The first week I took delivery from the dealer, I changed to a L46/L82 cam and installed 2.02" slant plug heads with 64cc chambers. This upped the compression to a little over 10:1 and gave me much more power with a shift point a little over 5600rpm. Engine probably made around 300 net hp. This was ok, but not as good a combination as the C4 LT1 that came out later.

Chuck

 

I agree that it isn't as sexy as a late LT1, but the later TPIs with aluminum heads had higher compression. Couldn't you at least give me that the TPI was a major improvement over the last 81 carbed cars?