I thought it was not until 72'-73' that the pollution regs forced catalytic converters/low octane unleaded and new underwhelming horsepower measurement standards on the US auto industry.:scratch2:

I think '70 was the last of the High compression motors. I COULD be wrong. We had a '67 Mercury Colony Park station wagon, Daddy ordered the biggest motor Ford would stuff in one, I'm thinkin' it was at least a 390, & it would HAUL @zz.. Then, in '71 we traded it on another Colony Park, IT had a 429-I THINK-but it was rather a Slug by comparison.

For a lot of cars horsepower numbers peaked in 1970. If you look at the Buick, the first year for the big block was 67 - in the big cars it was a 430 from 67-69. 1970 was the first year for the 455, and the 455 continued up through '76. I think only the '70 455 (given we're talking about engines that are completely stock) is said to be hotter than the 430s. The Buick 455 slowly declines in power from '71 through 74, but didn't really loose a lot of power until '75 which was the first year for the catalytic converter (and crappier low compression heads).

1971 was a downturn year. The auto manufacturers started building the engines to run on low lead/unleaded gas that was becoming the standard in the early 1970's.

Indeed. When 1971 came in compression was lowered (as was correctly put) to run on low lead/unleaded gas. Emissions controls also sapped horsepower, took a long time to get drivability and performance back to the old days.

Yeah- A buddy of mine colorfully referred to the low-lead stuff as "Mouse Piss Gas".

Yes, and the vehicles got their worst in the 1978-1980's era when horsepower got to below 200 even on 350 V8 engines on GM intermediates and full size cars, the era of the 160 horsepower Camaros, Firebirds, Grand Prix and the Regal.

Or my 1984 Riviera with a whopping 140 hp!!

Sorry, the manual I have is for a 1975 Buick, not 1970.

I had a '76 Cutlass Supreme Brougham, w/the 350. My Dad & I took it over to a guy near Boone, NC, he took all the pollution stuff offa it, & drilled holes in the air cleaner so it got as much air as it wanted. The only car I ever had that had the WONDERFUL, "Wahhh-WAHHHH !!" sound when you planted yr foot on the Loud petal. TINY trunk, & tiny back seat, but I could haul 2 Kegs of Beer in the trunk, & 3 in the back seat if I had to.. It rode REAL good w/all that weight in it..

used to flip breather top over to get that wahhhh sound.i had a 76 cutlass also.wasnt much stuff on it but it all came off.decent runner but nothing to get excited about.now my 1970 torino cobra jet,429 boss-that was something to get excited about!

yes - TEL was phased out for new cars, with no legal means for anti knock, it required a compression de-tune as well as ignition retarding and some other crap.

plus the insurance industry became weenies.

1975 was the monolithic converter for HC emissions for MOST cars, some other cars with smaller engines using lean burn or stratified charge methods were able to do without (the lowly chevette and many hondas come to mind)

Don't look now, but there are some holes in the side. :D

Wow very nice!!!!!

Please give her a pat for me :)

Same car as used in Matilda by Ms. Trunchbull, when it ran. Nicest clunker I had ever seen, I thought.