Discussion in 'The Bench' started by 442w30, May 22, 2020.
Was the LeSabre available with a 455? What is the A8 performance option?
Yes I believe it was available with a 455 in 1970 .
The LeSabre 455 option began in the 70 model year but the LeSabre 455 HP "big valve" engine began in the 71 model year. It did not have the stage 1 swirl polished valves or the same camshaft profile as a GS stage 1 engine. In other words, in 70 a Lesabre 455 would have a SR or a SF "small valve" engine depending on whether it was a 2 door or a 4 door. It would not have a SS "stage 1" engine.
The big valve engine was never offered in the LeSabre in 71...only in the Centurion and Riv GS
Not according to Buick. Look at the A9 option on the respective Factory wholesale order forms:
I assume that the confusion is that in 70, you could get a 350 cid 315 HP engine.
I just found this. I hope it can be expanded enough to read it, if not it is avail at www.lov2xlr8.no under the 'brochures US cars' link. The LeSabre Custom subseries had a 455 option. My guess is maybe the order form was diff for a Custom? Oh, and it gets better - the stock axle ratio is listed as 3.23 for 3 speed manual and 2.93 for automatics. Now the same brochure mentions the ratio for a Wildcat as 2.78. WHAT? My only guess is that maybe the axle ratios listed for the LeSabre are for either version of the 350, not the 455, which I would think would have the same ratio as the Wildcat. Pardon the assumption. Hmm, I wonder what a change from 2.78 to 3.23 would do for acceration? Pretty darn close to a GS 455 from 0-60.
The keyword for the 71 option is "Modified high performance 455" as opposed to the one offered in the LeSabre order form.
Adam is correct. The "Modified" 455 is the one with larger valves and slightly larger camshaft.
Brad and Adam —I would agree with you were it not for the fact that 71 Estate wagons and Electras do not offer an A9 option. Your interpretation would mean that there were two types of A9 options which makes no sense.
The 370hp 455 installed in the LeSabre is the same as the base engine as was installed in the GS, the Centurion, the Electra and the Riviera. It was not the Modified 455 as was installed in the later model cars.
The only thing I can deduce is that the A9 option code was different based on each model. There was no engine options in the Electra and Estate wagon because the only one available was the standard 455. Also the same in the Riv and Centurion, except that the modified high perf 455 with big valves was optional.
In 73, there was no high perf 455 in the Centurion, yet the 455 option was A9.
UPC code meant different things, different years.
Gosh, this is confusing.
Yeah, sorry Diego. We didn't really even answer your question. I wonder if someone has a LeSabre order form for a 70.
Maybe a "Buick Guru" has one and will chime in.
Here ya go.
Well that's interesting. The LeSabre Custom455 was ordered as a separate style, and not even listed on the option codes.
Well, it's not that. I guess I'm confused by the small-valve 455s vs. big-valve 455s. Seeing small-valve 455s offered in 1970 and then big-valve ones for 1971 hurts my head because that was the year low-compression heads were ushered.
Maybe someone can list the different 455s per year with respective hp rating and valve category?
Prob would help to show what the engine is analogous to (such as the 455/370 seems to be the same as the GS 455's 455/350?).
I think this may be more interesting than the question I answered.
Back in 1983 I bought a low mileage, 71 Lesabre off and older women whose grandson wrecked for $200 because it had a 455/T400 in it. Put that engine & trans in my 70 Skylark Custom. Also put in a 3.90 posi Ford 9" with my own homemade 4 link.
With headers and a 2-1/2" exhaust that car was amazingly fast and I never understood why. That 455 ran so much better than the 455 in my 71 Electra. It would rev to 6000 cleanly without flattening out at 5000 like the Electra. This explains why.