LT1 identity check

A few months ago the engine of my 1996 Roadmaster croaked. It had the tow pack with engine fan etc.

I found an online seller company who said they had an exact match 1996 engine with 68,000 miles and they showed me photos.

What has just arrived is not the engine I was ‘shown’. It is labelled Chevy Caprice, which I have no special problem with as it seems the same cast iron motor but it looks older/dirtier than the one shown and has no engine fan and subtly different ancillaries.

  1. where do I look for the engine number?
  2. can you tell the approx age of the engine?


You may try this forum. They would probably be more knowledgeable on the LT1 SB.

Thanks. Figured lumpers might know.
I’m on a Roadmaster forum too. The motor is so filthy I want to clean the right spot!

My memory i really being taxed here

I thought the LT1s had engine numbers in the same place as all SBCs-- on a pad at the front of the block just below the right cylinder head. I could be wrong.

Also I think all LT1s had “327” cast in the side of the bock


Thanks Doug. It’ll be buried under a load of plumbing and ancillaries then. I’ll see if I can get by without.

Got it!!!

If it is a Caprice, it is the same engine. Possibly small variation in cam timing or such. As to age, about the same as Brontosaurus. 94-96 or so. The RM platform and the Caprice platform are shared. My Lt1 came from a 94 Cadillac Fleetwood Brougham. Same shared platform. Back in the day cops used a lot of Caprices. Retired usually at about 100k, many went on to serve some more. Taxi or sources for lumps.

Installed in any platform the ancillary stuff covers any id’s…

If the Caprice engine is indeed that, it will be just fine. If the engine is healthy. All your “stuff” should bolt on.

The Camaro’s and Corvettes, had a somewhat related engine. Hotter cams, alloy heads, etc. If it is one of those, it will bolt in as well, using your “stuff”.

How serious is the croak??? Fixable in terms of practical and $'s…

The recycle yard that provided my engine delivered it clean, pressure washed. Much easier to work on…


Came up with a quick ID method.

If it has the following, it is an LT1 and will fit right in:

  1. Optilite “distributor” off the nose of the cam. Think replacing either. A real pain in situ.

  2. The water pump is driven of a gear in the valve valley. The shaft is fragile. don’t ask…

  3. A visual comparison of the Brontosaurus intake with
    the “Caprice” unit. Alike or very similar…

I make these comments thinking of the roughly similar predecessor engines. The L98. And possibly the less able unit that was in Brontosaurus I.

Is the donor car available? or at last most of it???

An “on the ground” compression test might be a good thing to verify a degree of engine health…

Removed from a wreck. Good!! It ran!!!

Removed from a . “plumb wore out car”. Not so good…

Oh, what fun awaits you!!


I had converted a Jag using a Camaro motor. When that car was totaled, I contemplated using the motor but that did not work out. I ended up with a 94 LT1 out of a Caprice Interceptor [9C1]. The earlier comments are accurate about that motor being found in a number of vehicles of that era.
What is of more concern is the bait-and-switch tactic. I would have a mechanic do a leakdown test on the motor. Even if proves to be satisfactory, I would still write the seller and tell them you want either the engine you were expecting, or a partial refund. That kind of business practice is simply fraudulent.

Unlike the $2150 I lost via a fraudulent ad here on J-L, the engine story had a happyish ending, thanks to PayPal.

I was able to show the correspondence and seller photos did not correspond to my photos of the engine supplied. The seller said I should drop my PayPal complaint and they would supply a correct engine but PayPal warned me not to withdraw until I received the right engine.

I told the seller to take the wrong engine away but they have declined to spend 2-3 hundred dollars shipping it. So I have my refund plus the engine, which I will strip and swap parts on when weather improves. The three garage bays are full, so not looking forward to working outdoors even if I buy a canvas car port/garage.

Did I miss something? Wanted a compatible RM engine for Brontosaurus II ? what did you get? An Lt1 from a Caprice? That woud work if healthy.

Or something else not related to the depiction… What did you get??

Seems like you won, after a fashion???

Paypal Protection. as well as credit card protection is a good thing…


Make sure it’s not the “Baby LT1” version of the engine - which I believe some Caprices had.

Aye, I seem to recall that Pete’s Brontosaurus I was so powered.

Pete: Fire it on the ground or at least do a compression test… if you have not already done so.l

It’s an injection engine so there’s no hanging a squeezy bottle of fuel off a stick for a carb startup.

There’s no transmission so no bell and no starter cranking.

The plugs look as good as impossible to reach, even with the engine on a pallet! Who designed these things!? Been spoiled with the XK or even V12.

The big difference is this engine has no tow pack and mechanical fan, which I specifically asked for and he specifically said would be fitted as in the photos he sent. I will swap the ancillaries over but every nut and bolt looks like it will snap/crumble once I start…

I would love to leave off all the spaghetti mess of wires, tubes, valves etc for EGR and the rest, but I expect the ECU would throw a fit and OBD2 codes. I will put a new water pump and distributor on it, plus plugs and wires (is Rock Auto the cheapest?) but that’s it.

Is it easier to pull the old engine with trans and fit trans to new engine, or leave it in car and just swap engines? This will be done outside in warmer weather. .

Depends on tranny, Stick or auto? If stick, I would go with engine and tranny install. If auto, just the engine.


If the palletized Lt1 has a flex plate, I think you can crank it on the ground. if you have a starter. Not that hard to pull from the car. Done it oh, so many times!!! The starter is bolted to the block by two bolts. Vertical not horizontal. You can check gear mesh easier than in the car. Shims might be needed. None of mine ever did??

That will at least enable a compression test or even a leak down.

Aye, FI is more complex than a bottle feed. Never did it. In theory feasible. More connections, aye.,

Is it OBD I or II. I will merely fail to douse the check engine light if the stuff is not functioning. EGR, etc.

It seems easier to Just plug in the harness as it is in the car. EGR and that stuff ain’t all that bad. Your air pump may or may not work. so???

I vote for pull the engine and trans together and reinstall together. less under the car work. good thing.

Was the old LT1 failure serious???


I would like to go to stick but it’s an electronic box so a computer would complain. Plus heavy hauling is tow-pack auto territory so I’ll save stick for if the trans ever blows.

No starter but I did replace the car one so good idea if pallet structure allows access. It turns by hand and supposedly is a 68,000 miler but looks way more. Will do compression test and maybe leakdown. Old engine was supposedly 0 on one and 50 on another though it seemed OK to me.

Cast iron heads mean it will stress ny crane even without trans.

I only had a medium duty “cherry picker” to do the swap on my car. A pro helped me. Out with the DOHC and BW together. In with the LT1 and 4l60E together.
A balance bar would have made it easier. Oh, and a trolley jack for the trans in each case for part of the way…

Old on 6 and sometimes 7!!! Gee, a much simpler valve job might have been the cure ???

I swapped in new plugs when the engine was on the ground Actually on a large tire !! Easier than in the car.
Aye, the plugs are under the exhaust and access for some is tight, but doable. What was real “fun” was new plug wires, in situ. Why I did not swap them in before has no answer…


The reason it failed was a bad replacement dizzy that AAA swapped under warranty but it still didn’t run. Then they did compression and told me to take it away. Nexf shop agreed engine was clapped out and recommended I scrap the car. Not bloody likely - they are going up in price now. So I will do some wrenching when I get time and see if I can get spark. Could an LT1 be retro-fitted with carb and normal coil plus distributor if all else fails? I’m guessing not…

Peter. To answer that question you might try a street rod forum. They are messing around with that stuff all the time. My guess would be yes but I really do not know. I do know that years ago it was common to switch back the earlier fuel injected small blocks to carbs for supposedly more power.

I’ll look it up if/when I ever need to know (I hope never). It’s just that I’m better with wrenches than computers

Having spent my life ‘adding lightness’ and substituting bit from quicker models onto my bikes and cars, I have to admit that for pulling heavy loads, a large weight at the front, making power from low down with small ports and cams, make a better recipe than a sportier motor. .