In that lingo, the blue engine means it's a Pontiac motor (produced by the Pontiac Division of GM) whereas an orange engine means it's a Chevrolet motor (produced by the Chevrolet Division of GM).

Post a photo of what you've got and we'll identify it.

From the clues you've given, it sounds like a Pontiac 400 to me.

thank you. Battery and starter are on the drivers side. It has the 400 stamp on the block and has the VIN that matches the car vin. It has a block date of H161 (August 16, 1971: car was built in September 71). On front of block it has stamped 0017194 YS (I think Im not in front of it, sure of YS). I doubt have good pics right now.

BTW: does that means there is no truth an american engine versus Canadian engine. Is it just that red symbolizes Canada and blue symbolizes usa?

First I want say that Ive read posts and like these, Im always impressed with the information that you guys have just on the top of your head! Im learning quickly.

second maybe Im a bit dense here: were pontiacs built in US while chevys were built in Canada?

Just a couple of things, there were never any Chevy 400 small blocks offered in the LeMans car line. In the Library is a thread with engines used by year and the 1972 LeMans engines are there. 

Pontiac were built in Canada depending on model, same goes for Chevrolet. In 1972 LeMans was built at Ste. Therese factory and you could get one with different engines. I'd say most were Chevrolet 350 engines and painted orange. Very few would have been with Pontiac blue engine 400 4bbls like you have and even less with the 455 blue Pontiac engine. 

The blue block vs orange block vernacular dates back to the sixties. Generally is was an easy way to know if your Pontiac was a US car or Canadian car since full sized Pontiacs used orange "Canadian" engines exclusively up until 1970. in 1970 some Canadian built Pontiacs began getting blue US Pontiac engines and it began a mix of engines from then on. 

Was a Pontiac engine more powerful than the counterpart Chevy? That's not easily answered because the specifications vary so much but in the era that this was coined Pontiacs here had 283's and 327's mostly and a US car would have been a 389 so in that case mostly yes, but then there is the size and weight factor of the smaller Canadian cars. Lots of cases of 327 Parisiennes blowing 389 Bonnevilles away.  

Most US enthusiasts and many Canadians do not consider Canadian cars with orange engines as legitimate Pontiacs although as you can see this entire forum exists to refute that. 

-- Edited by 73SC on Thursday 4th of October 2018 10:08:46 PM

Only a 5 year old with a two watt bulb for a brain would paint a Pontiac engine red.

Having said that Pontiac did supply GMC with V8's from 1955 to 1957 and GMC painted them Red to distinguish them, the old GMC,162 hectare factory was right on South Opdyke Road in Pontiac.

Pascal, your papers say 200 HP but that's wrong, it does not consider the dual exhaust N10 option. The engine with duals was rated at 230 HP. This is just a minor oversight on GMVVS documentation because the paperwork shows the basic engine with single exhaust, its only once the option is chosen that the rating changed. 

Yes my error as I was posting from memory on the HP rating with duals. Now that I access my documentation the engine is rated at 250 HP with duals. Nonetheless my premise and assertion that the GMVVS did not consider the N10 option is correct. 

In 1972 only the six and 350 with 8.5:1 compression are Chevrolet engines, produced by McKinnon Industries in St. Catharines, Ontario. No Pontiac engines were ever produced in Canada so they had to be imported. 

Being a 1972 your car is a total anomaly because it is actually a carry over 1971. There was a huge strike by the auto workers and what we know as the 1973 LeMans was intended to be the 1972 LeMans so GM couldn't accomplish the changeover because of the strike so in your case early 72's were actually 1971 final production at Oshawa. After that the LeMans was built in St. Therese. Your engine has to have a 1971 ID because that's when it was produced, it is numbers matching but it was installed in a 1972 model car. This sort of discrepancy with numbers happened all the time with early and even late production models. There is virtually no difference in a 1971 engine and 1972 engine except in compression ratios and methodology used to rate horsepower. For example 1972 is net HP, 1971 is Gross HP. Your 250 HP 1972 rating would roughly translate to 310 HP in 1971 rating. 

 

Here's my understanding of this subject;

1) Every division had it's own powertrain division.

2) Most, if not all Canadian build Pontiac's were advertised as having a "Pontiac V8" before they were sued, and started being honest about the source of the engines.

3) pre-smog Chevrolet engines were painted orange.

4) 1971-1973.5 Pontiac engines were painted a light blue (the paint actually changed with developmental changes)

www.pontiacpower.org/enginecolor.htm

5) I believe that before Pontiac (as in GM of Canada's Pontiac division) was sued for misrepresenting the engines sold to most of their customers, the Chevrolet sourced V8's intstalled in these cars were painted gold, and have "Pontiac V8" decals affixed to their air cleaner lids.

6) the term "American Big Block" is one of several used to distinguish blocks from a confusing point in time;
As an example, a 1971 Lemans could have been ordered with a 350, if it was a Canadian built car, it was a Chevrolet sourced 350;
That same Lemans could have been ordered with a 400 or a 455 - both of which would have been built and assembled sate-side, and shipped to the manufacturing plant - these were coined "American Big Blocks".
I believe that for simplicity, most Canadian built cars used Chevrolet drivetrains, and most Canadian orders for cars with REAL Pontiac V8's were actually just built state-side, and imported into Canada.