Anyone (Carl) remember the 366T Engines

GLHS60 · Poncho Master!

Anyone (Carl) remember the 366T Engines

SGS Welding · Guru

I have read a lot of info about Chevy engines over the years

this was something new ! Thanks Randy!

poncho62 · Poncho Master!

I bought a 68 el Camino what someone had dropped one of those slugs into. I remember it had the dual thermostats, but never worked on it. I yanked it out in favour of a 454.

4SPEED427 · A Poncho Legend!

First time I ever heard of or saw a factory gear drive on a big block. Never too old to learn...

GLHS60 · Poncho Master!

Strangely, the only ones I saw were gear drive, (2 or 3) possibly Marine or H.D. aeronautical.

Thanks
Randy

GLHS60 · Poncho Master!

Just found a reference 1966-68 366 and 1968 427.

Thanks

Randy

https://books.google.ca/books?id=Mx7cnFWOmK4C&pg=PA32&lpg=PA32&dq=366/427+T+gear+drive&source=bl&ots=KCmltOYTOA&sig=ACfU3U1PN9K74Ipb447RLImoP_8qsgKbMw&hl=en&sa=X&ved=2ahUKEwio8cDC5bzhAhULAnwKHbo0Bj0Q6AEwA3oECAgQAQ#v=onepage&q=366%2F427%20T%20gear%20drive&f=false

pontorquer · Poncho Master!

Guy I knew use to buy the cheap 366T engines for their cranks ...

4SPEED427 · A Poncho Legend!

I knew a guy like that in Morris......his garage used to be full of the cores he bought at the dealership he worked at and then stripped them for the cranks!

68 Grande · Guru

First I had ever heard of the gear driven cam being used in marine and truck engines was when I was reading in the "How to Hot Rod Big Block Chevy's" book by Bill Fisher and Bob Waar. They talk about this subject on pg 59.

And like Carl says in the post above, many of the cranks in these engines were parted out to find homes in other engines. Case in point, my 6223 forged crank in the 68 Grande is not the orignal crank. Somehwere along the line my engine turned a bearing, wrecked the crank and this 6223 found a new home in my 396.

My 396 came from the factory with a nodular cast crank, but when we opened the engine up on a rebuild in 2017, surprise, there was a 6223 forged crank in it. And, you could see the very faint "366" written on it with white paint. Polished it up and went right back in.

Pontiacanada · A Poncho Legend!

Carl Stevenson wrote:
I knew a guy like that in Morris......his garage used to be full of the cores he bought at the dealership he worked at and then stripped them for the cranks!

Was his name Carl? wink

4SPEED427 · A Poncho Legend!

Pontiacanada wrote:
Carl Stevenson wrote:
I knew a guy like that in Morris......his garage used to be full of the cores he bought at the dealership he worked at and then stripped them for the cranks!
Was his name Carl?

How did you know? Do you know him?

Yams · Veteran Member

I have no idea about the gear drive cam, but I do know that the cranks in a lot of them were steel.

4SPEED427 · A Poncho Legend!

I would suspect all the tall deck blocks had steel cranks. I've sure never seen an exception so far.

Pontiacanada · A Poncho Legend!

Carl Stevenson wrote:
Pontiacanada wrote:
Carl Stevenson wrote:
I knew a guy like that in Morris......his garage used to be full of the cores he bought at the dealership he worked at and then stripped them for the cranks!
Was his name Carl?
How did you know? Do you know him?

Just a guess ... I heard about a guy in those parts that liked performing surgery on big blocks.

seventy2plus2 · Canadian Poncho Superstar!

This thread is talking about a 366T engine. Dumb question, is there a difference between a 366 and a 366T engine?

68 Grande · Guru

I thought all 366 and 427 truck engines were only T or Tall Deck engines? But, I could be wrong but I thought that is the only way they came.

-- Edited by 68 Grande on Monday 8th of April 2019 08:56:11 AM

Prefectca · Poncho Master!

As far as I know all the 366 are tall deck truck engines. The T was used to identify the engine as a tall deck truck engine. The 366 and 427 truck engines had a taller block to allow the use of longer connecting rods. What this did was lower the RPM when the engine produced peak torque. This allowed the trucks to pull better at low speed. In the 80s we had both the 366 and 427 engines in C-70 Chevy trucks. For our use we didnt see much difference between the two, except that the 427 used a lot more fuel. Paul

GLHS60 · Poncho Master!

seventy2plus2 wrote:
This thread is talking about a 366T engine. Dumb question, is there a difference between a 366 and a 366T engine?

I see some are up earlier than me!! ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

There are no dumb questions.

As far as we're concerned there really isnt any difference.

All 366, no 396, many 427 and possibly some 454 Engines were Tall Deck and received the a T designation.

Tall Deck Engines were workhorses that came mostly in Med Duty Trucks, not pickups.

In a nutshell, there were no non Tall Deck 366 Engines.

There were 454 Truck Engines but I've found no proof they were Tall Deck.

Would love to see some evidence showing the approx 1980 454 Med Duty was a Tall Deck.

There are some later Tall Decks as well, both OEM and aftermarket.

Thanks

Randy

-- Edited by GLHS60 on Monday 8th of April 2019 09:11:32 AM

4SPEED427 · A Poncho Legend!

Actually the 366/427 truck rod is the same as the 396/427 car rod. The height in the block was changed to accommodate a 4 ring piston.

4SPEED427 · A Poncho Legend!

Randy, yes the 454 medium duty was a tall deck. The intake gasket is the proof. It's the same for 366 427 454 in the medium duty trucks and of course it doesn't fit from the car/pickup engines.

GLHS60 · Poncho Master!

I would sure like to have some indisputable proof.

Not doubting you but many who should know dispute even the existence of a 454 in a Med Duty.

I even posted a picture from a truck brochure with a picture of both Engines side by side.

Picture wasn't clear enough to see any exact details that would confirm.

Brochure called them 7 and 7.4 L, not CID as I remember

I thought I saved the picture but cant find it.

Thanks
Randy

4SPEED427 · A Poncho Legend!

Well, I don't have a picture of one but the ring set, the intake manifold and the intake gasket are all identical on either a 427 or 454 in a 1980 C70. To me that says there is no possibility of it being anything but a tall deck.

4SPEED427 · A Poncho Legend!

And I saw one with my eyes mid 80's when I worked at the Pontiac dealer. We had a customer who brought his in for service.

Prefectca · Poncho Master!

Thanks Carl, I was told many years ago that the tall deck engines had longer connecting rods to change the torque curve for truck applications. I also knew about the four ring pistons but didnt know that the pistons were the reason for the change in deck height. I was told this by an engine rebuilder and never thought about it, I just assumed he knew what he was talking about.

Paul

GLHS60 · Poncho Master!

Carl Stevenson wrote:
And I saw one with my eyes mid 80's when I worked at the Pontiac dealer. We had a customer who brought his in for service.

I'm not arguing, just fishing for info like a casting #or something.

I eventually found a casting # for a 305 4 bolt main.

Thanks

Randy