Octania

OK, now I need help from youse guys.

In the era of 2A, 3A, 5A, etc heads:
after 1976's #8 heads were no longer used...

is there such a thing as a better flowing head, with castings similar to all others of that model year? The rumor was of a "Canadian issue" head. Maybe what we have is Canadian cars getting large port 3A heads or 5A after USA engines had gone to the small port 6A or 7A castings?

captjim

IIRC, most cars that would come with SBOs in the states came with SBCs in Canada.

Allan R

Not necessarily true. We did get some of the SBCs in 78 when Olds engine production fell short. After that I believe we got the F code 350 and notorious tire melting R code 260.

captjim

I did say "most" And in the 80s did any Cutlasses get 307s?
I can't believe they actually put those 260s in big cars, what a turd that engine was.

cutlassefi

My in-laws had a '90 caprice estate wagon, had an Olds 307 in it. What a pig.

Allan R

No problem. Just that the way you said it suggests we mostly got Chebby instead of the good stuff.

re: 80's Cutlass? Yes, 1980 442's got a 350, After that (1981-early 88 RWD) Cutlass could be built with the 231, 260 or Y code 307. 1983-84 442's automatically got Y code 307's.

I'm in total agreement with your statement on the 260.

ThePackRat

Never heard that before, but if there was an actual difference in the heads ...

I would have guessed it to be more of a smog pump boss'es without vs with then anything else ... as Canada's emission requirements weren't as strict as the US - thus many things would tend to happen a few years later there vs here.

In the regular 78-80 Cutlai ...

The mush cam-shafted Chevy 305 [VIN H IIRC) was often the biggest V8 found in them.

Otherwise ... the biggest Oldsmobile V8 in the Cutlai line from 78-80 was the 260 VIN F.

350 diesel VIN N's & the 442/HO 350 VIN R's excluded of course.

In 1981 things changed :

Regular USA Cutlai equipped w/a V8 no longer got the disposable Chevy 305's.

They either got a 260 or a 307 (believe 82 was the last year for the 260).

Canadian Cutlai equipped with a V8 got Chevy 267's or 305's.

The same exceptions apply here as they did w/the 78-80 cars.

In regards to the big cars (Canada) .....

Other than the infamous Chevy fiasco of 1977 ... I'm not sure if they "officially" followed the same deal the Cutlai did in 78-80.

I do know the Pontiac 301 made it in a few D88's (even in the US IIRC).

Otherwise ... I'm pretty sure they always had Olds V8's.

I believe it was sometime right around/after the regular big car production ended ... in which all the big wagons got the Olds 307.

ThePackRat

VIN code "Y" was the standard 307.

VIN code "9" was the higher output 307 found in the 83/4 Hurst - 85-87 442 & also rumored to have shown up in a few late 80's Caddy FWB's.

joe_padavano

I'm afraid you would have guessed wrong, since EVERY Olds head cast since late 1965 has had A.I.R. bosses and bumps in the exhaust ports. I was under the impression that the 6A heads were only used on Canadian cars in the mid-1980s, but I have no proof of that.

ThePackRat

Bad wording on my part ...

Drilled out holes for the tubes is what I should have said.

joe_padavano

Fair enough, but Olds castings were the same whether the A.I.R. bosses were machined or not. Witness the B and C heads used on cars with Calif emissions in 66 and 67. These same castings were used on 49 state cars without the machining.

olds 307 and 403

Most Canadian Cutlass were sbc powered, except the 88 model year and the 442, Hurst/Olds. All the rwd Delta 88, 98, Buick Lesabre and some Caprice were Olds 307 power. Only difference was my 5A heads had plugs where the air tubes would go. Never seen the 6A that I can think of, maybe on one 85 wagon we pulled apart years ago. Pretty sure after 85 all were 7A headed turds.

DoubleV

I don't think there was any such thing as a special high flowing Canadian head other than the 6A 307 heads, which according to a Canadian who used to post on the Olds forums, retained the larger exhaust ports of the 5A heads compared to the 7A heads here in the states which had the small exhaust ports. I don't know how long the 6A head lasted there in Canada ( maybe some trickled into the US? ) until they too switched to the 7A.