Technical BB chevy heads . peanut port

What year did the small "peanut" intake port heads first come out ?

They are way smaller intake ports than the old oval port heads.

 

pickup truck 454 engines, starting in the 70s.

 

To narrow it down, I'd say 1976 or 1977...

 

YES...they were much smaller than the early...original "oval port" heads. Don't know exactly, mabe, about a third smaller than the oval port heads. Never actually measured a set.
Only good for general usage.

I once bought a pair of the original, oval port heads to replace the peanut port heads on my Suburban tow car, when I was building an altered roadster. Then everything went to hell...

Mike

 

They were used on the 427 tall decks too.

 

I didn't know they were used on the medium truck motors....I thought those got oval ports, but smaller valves?

 

I had thought the tall deck engines were made sometime in the ‘60’s?
Were the peanut port heads made back then for them?

 

1978. I specifically asked this question to a tech guy at Mr Gasket, as I had a choice of 2 factory 1/2 ton 454 trucks I was looking at; a '77 Heavy Half Silverado and a '78 C10. I went with the '77 because I thought the engine would wind up in a hot rod, and everyone "knew" the peanuts were junk. Peanuts can be made to work in a street car, but up in the 5000 RPM range the ovals start to pull away. Back in the 90's I threw a set in the dumpster, no one wanted them. Now people are resurrecting them. Most oval port engines were painted orange, peanuts were either blue or black. HEI came in '75 for rats.

 

They were made the same time the "normal" big blocks were made, although I don't know what happened when the Mark IV went away in the early 90s?

so at least mid 60s to early 90s.

 

Had no idea the tall decks were made the same time and lasted so long.

 

Apparently the medium duty truck engines still required the 4 ring pistons and added cooling provided by the dual thermostat intake manifold used on the tall-deck design. I know they made 366 and 427 tall-decks, but did they ever do the same design on the 454?

 

I have a set of heads from a tall-deck 427. It came out of a late 70s medium duty truck. They look to be regular oval-port heads. I will drag them out and post the casting numbers when I get a chance.

 

No tall deck 454s......

 

measure the valve diameters too, for fun

 

There were actually small oval ports used in 65 on 396 high compression car engines. They often get referred to as peanut ports because they are smaller than the common larger oval ports that the majority of the oval ports produced were. These small oval ported heads are not the truck heads from the 70s that are commonly referred to as peanut ports and the air flow in them is different from peanut ports. The small oval ported mid 60s heads were either open chambered or closed chamber heads. They work well in under 6000 RPM applications.

 

Local truck pullers will source peanut ports to keep velocity up in their relativly low RPM grunt motors.
Tall deck heads have something like 100cc chambers and will bump compression on a standard deck 454.
They used rotators under the valve springs so you have to get thick spacers made to run without them.

 

Not bad for just running around with a decent amount low end torque.

 

1978 eh?.... I guess thats about right..... about when they started choking horsepower cause to try and prevent smog
My friend 85 dulley truck had 'em, and several 454s saw that were pulled out of motorhomes had them

Im looking at a 454 motor 1973 cast date, 3999289 block cast number. Im waiting for the dude owner to pull a valve cover and give my the head cast #
Ya thing a 1973 block would have came with the oval port heads and not peanut port?

 

73 would be oval port, open chamber heads. But that was 50 years ago when it was new, who knows what's on there now

 

Regular oval port, probably 781's or 049's, if it's as Squirrel says, untouched. They were the best flowing oval port heads.

 

Maybe Squirrel can answer this one. I worked on GMC school buses at the start of my career, they were all 366 big blocks, mostly carburetors, with a few EFI ones later on. The carbureted ones, MY 1985-86, had cylinder heads marked “HI PERF” under the valve covers. They had oval ports. I’m sure these were OEM installed, these buses were less than 5 years old at this time. I’ve forever wondered about the Hi Perf cast into these.

 

The block may still have the numbers stamped on the deck pad, might give you a good insight of where it came from. If it's from a p*** car, or truck I wouldn't think it wouldn't have the peanut ports. The 427 tall we had, had them but it came from a huge wheat truck.

 

The way the engine casting process works, is kind of weird....apparently the molds for the sand cores were marked for what engines they were used with, so you might find (on a block) the HI PERF, P***, and TRUCK wording...all on the same engine. Then on another part of the engine it might just have one of them, or maybe two. On the top of a head, seems odd that it would say HI PERF, if it's an oval port head.

so I can't answer your question, but it's something that doesn't surprise me.

 

^^^^^^^yes^^^^^ I have seen 454 2 bolt blocks with those cast into them, I think it was common.

 

It should have the good oval ports.possibly 781s

 

Heads are 336781

 

look for the casting date too, you can see when they were made. Letter followed by two to four numbers, such as D 14 3

 

1973 date as posted earlier

 

Check for a wide parting line on the rear crank flange

 

yep, forged steel