How do I identify an LT1?

Hi guys and gals,

What are the identifying features between an LT1 and the 4.3 billion other SBCs? Thanks,

Mid

Distributor is in the front cover area instead of in the back is the big giveaway. Also center-bolt valve covers, SEFI, and weird coolant lines coming out of the back of the heads IIRC.

LT1:

SBC:

If by chance you're looking at whole cars as donors, look for a P in the VIN at the 8th position.

The water pump is the absolute dead giveaway. Its internally driven on a little splined shaft that sticks off the cam.

Thanks guys!!

Be weary, '94-'96 Caprices were available with a 4.3l V8 that looks exactly like a 5.7l LT1. The 4.3l has a vin code of W in the 8th position.

oh no. if you buy an LT1 you should invest into opti-spark replacements ASAP. Or convert to the delteq ignition system or use the LS1 coil per cylinder coil packs and buy a $400 module box to run it. Other wise you'll be kicking yourself in the nuts. I am so happy I don't own an LT1 anymore.

We have had 2 Lt1 Wagons and amassed well over 400,000. Only ever had to replace 3 optisparks. If you get the 96 one it's vented, or you can vent a pre 96 unit.

the Iron heads outflow the aluminum ones

caprices have crank fans , Impalas have electric fans

didn't someone post up how to adapt a Northstar coilpack for virtually nothing?

and that little 4.3 V8's crank in a 5.7 Lt1 gives you a high winding 302 LT1... I think superchevy or hotrod did the buid

i got 110k out of my first optispark, then i was replacing them by the month for a while, finally got one that worked and then bam semi hits the trans am

I have well over 125k on a stock Opti. The "opti" part (the optical pickup trigger) is a model of beauty. The "spark" part isn't the greatest. But there is no need for a complete expensive new unit. The aftermarket has caps and rotors that fix the "spark" part.

I also want to clarify something AutoXR said... all B-body LT1s had electric fans. Some of the HD versions and Buick roadmaster/Olds Custom Cruiser/Caddy Fleetwood had an additional bracket with a pulley that operated an additional mechanical fan... but they still retained the electrics.

LT1 iron heads do in fact flow more than the aluminums. In fact when the LT1 iron head came out, it flowed so well that they designed a wimpier (191/196) duration cam for the B-body to keep things in check. After all, no one would want an F-body if it was advertised with less power than a Caprice. The intake port on the LT1 iron heads was directly carbon copied for the Vortec head in 96, so when estimating power, its safe to use Vortec head flows as a model for LT1s with iron.

There are several head porters of LT1 aluminums. My personal choice is Advanced Induction. All CNC, top notch work, and not too expensive. They have a ton of low 10's time slips in B-bodies to back it up.

Here's my LT1 car. Its currently mostly stock under the hood with some computer hacks, but I have a ton of parts in boxes; forged stroker crank, forged H-beam rods, a T56 six speed, 4.10 gears, Eaton Posi with 800# bias springs, a GM846 cam, and soon I'll have those AI ported aluminums. I'm looking at putting at least 425 to the flywheel.

And if the engine is covered by a huge air cleaner that looks like home plate that's another clue.

For some reason I'm convinced that the Opti's on the b-bodys last a lot longer than the ones on the F-bodys. Mainly because they prolly aren't driven as hard as F-bodys. I never tried aftermarket optis, I only worked with re-mans and new AC Delco. I went through 2 re-mans and 3 AC Delcos in two months. We couldn't really figure out what it was, whether it was the ICM shorting and causing the whole system to go or what. Finally one started working.

That is when I started doing all the research on Delteqs and the LS1 style ignition system, and building your own custom style one.

It's the perfect example of some crazy mid-90s technology that people thought would revolutionize the industry when in fact everyone tended to hate it.

Oh and nice car. I would love to have one for a DD but damn they are still redic expensive for one in decent shape.

You can have mine for $225k

The Delteq is getting great reviews by B-body guys, but its so darn expensive. I need to read up on the GR options for upgrades.

Buying a Delteq system is just as much as putting an MSD box on there, or and MSD opti, or a couple of AC Delco replacements.

You can go to a junkyard and buy a bunch of those coil packs for cheap though. They had them on the Aurora V8s, all 3.8 V6 cars, and so on. They are on a lot of cars that end up in the junkyard. Then you just buy the cut-to-fit do-it-yourself spark plug wires, and you just need to buy the rest of the system. It'll save you some money.