1973 GTO Road test unearthed

73SC · A Poncho Legend!

1973 GTO Road test unearthed

67BBSD · Canadian Poncho Superstar!

wow-thats a pretty great 1/4 mile time for a stock car

65Camino · Uber Guru

Nice! Bet the Canadian 454 version was quicker!!

427carl · A Poncho Legend!

13.7 at 99 is pretty good for a "heavyweight"

3:42's is a lot of gear for a 3 speed auto (back in the day)

love the History

73SC · A Poncho Legend!

65Camino wrote:
Nice! Bet the Canadian 454 version was quicker!!
Might be close. I don't think that is a real 1/4 mile time though, that must be the one for a Trans Am SD455.

-- Edited by 73SC on Wednesday 23rd of May 2012 12:30:07 AM

4SPEED427 · A Poncho Legend!

I hate to say it but even though I'm a big block (as in Canadian Poncho "orange" big block) kind of guy, my money would be on the 455 all the way on this one, by several car lengths is my guess.

BillyGoat73 · Veteran Member

That's interesting seeing the Canadian engine offerings. I don't think any Canadian built GTOs would have received a Chevy engine, especially since the base engine was the 400-4V and the only other option in the States was a 455-4V automatic.

68 427 · Poncho Master!

I SEE THAT IT SHOWS A 454 AVALIBLE FOR THE LEMANS AND LEMANS SPORT COUPE. IS THERE ANY KNOWN TO HAVE BEEN BUILT?

CdnGMfan · Canadian Poncho Superstar!

I must say that seeing the 454 on the option list for the Canadian 1973 Lemans is truly a surprise. I have never heard of one. They were not offered in 1972 or 1974 with the BBC. As far as I know all GTOs were Pontiac powered only. The 400 4-barrel Pontiac (L78) was offered with a h.d. 3-speed, a 4-speed or TH400. The 455 Pontiac (L75) was TH400 only. I wonder if the 454 Chevy (LS4) was offered with the M21 4-speed & TH400 like they were in Chevelles?

I also notice the horsepower & torque figures are different than what Chevy was publishing for the LS4 for 1973. It is listed in Ray's 1973 Lemans brochure as 270 net with 390 net lbs/ft of torque. In Chevrolet passenger cars except Corvette it was listed as 245 net (215 net with single exhaust system on the full-sized wagons). Corvettes were listed as 275 net. Light duty trucks (pickups, Suburbans & chassis cabs) were listed as 240 net @ 4000 rpm & 355 lbs/ft @ 2800 rpm. I don't have available right now my Petersen Complete Book of Engines for 1973 with all the SAE specs in them, but it seemed to me the torque figures were about 380 lbs/ft. I guess the rpm is the determining factor as to where they rated it.

Fascinating post, Ray!

Evil Stu · Member

CdnGMfan wrote:
I must say that seeing the 454 on the option list for the Canadian 1973 Lemans is truly a surprise. I have never heard of one. They were not offered in 1972 or 1974 with the BBC. As far as I know all GTOs were Pontiac powered only. The 400 4-barrel Pontiac (L78) was offered with a h.d. 3-speed, a 4-speed or TH400. The 455 Pontiac (L75) was TH400 only. I wonder if the 454 Chevy (LS4) was offered with the M21 4-speed & TH400 like they were in Chevelles?
I also notice the horsepower & torque figures are different than what Chevy was publishing for the LS4 for 1973. It is listed in Ray's 1973 Lemans brochure as 270 net with 390 net lbs/ft of torque. In Chevrolet passenger cars except Corvette it was listed as 245 net (215 net with single exhaust system on the full-sized wagons). Corvettes were listed as 275 net. Light duty trucks (pickups, Suburbans & chassis cabs) were listed as 240 net @ 4000 rpm & 355 lbs/ft @ 2800 rpm. I don't have available right now my Petersen Complete Book of Engines for 1973 with all the SAE specs in them, but it seemed to me the torque figures were about 380 lbs/ft. I guess the rpm is the determining factor as to where they rated it.
Fascinating post, Ray!

Interestingly the Pontiac 455 ratings are slightly different also. The 455 was rated in US sources at 250 horse (215 with single exhaust) as opposed to the 255 seen here. Torque rating is the same at 370 but the RPM usually stated is 2800 and not the 3500 in this brochure. I think this last is an error, it would be unlikely that the 455 would see peak torque several hundred rpm higher than the 400.

I sure would like to see a 454 4 speed Lemans or Lemans Sport, that would be a cool car. It does seem to imply that it would have been available...