Dirtdigger04

Hey, I am looking into putting a Chevy 427 engine into my 68 corvette. I found a good deal on a Chevy 427 tall deck, and I need some information on this engine before I buy it. Will my stock transmission that fits a regular 427 engine fit this engine, and will this engine fit in my corvette? What is the performance specs of this engine in its stock form? Thanks
-Mario

540 vette

I think you will have problems with the headers. Heads sit higher. You will need another distributor and intake, or at least the spacers.

The 427 tall deck was a truck motor. If you want to stroke it you could make a monster big block.

TimAT

The tall deck blocks were used in trucks- C60's,C65,C70. THe deck height is 10.2 from the crank centerline, the normal deck height is 9.8. With the taller deck, the heads set farther apart making the overall width greater. Clearance in a Vette is an issue from the get go and having the extra width doen't help. I've seen some tall deck blocks in Vettes, it is something that's possible, but there is a host of problems that go with it.
Aftermarket makes intakes and distributors that fill the specs of the tall deck so that's really not much of a problem. And there are also spacers made that will adapt standard deck intakes to the tall deck. Headers will be a different story.

Corey_68

Tall decks were also available in marine applications FYI.

TheSkunkWorks

In stock form the 427 tall decks were dump truck and boat motors. As I seriously doubt you'd want to put a standard 427 truck engine in your 'vette, the performance specs you should worry about are those of the particular build you're looking at. IMCO if it doesn't have at least 6.535" aftermarket rods, it's nothing special, even if you're willing to deal with fitment issues.




FWIW, I still have one good 10.2" BBC bare block and one 10.2" BBC "boat anchor" available. I'll make a good deal on the former, while the latter is free to anyone that might can use it for mocking up; local pickup either way. Sorry, sold my intake spacers last fall.

Garys 68

Dont bother with the trck tall deck. Typically not a hipo motor. Made for low rpm, lots of torque. The tall deck boat motors are siamesed, strengthened, and can be bored an stroke to 540, 572, 588, etc cid and turn over 1000hp. No comparison to the truck tall decks.

Mooser

Friend of mine put a tall deck into his 68, all kinds of issues with fit.
Headers needed to be cut and re-fit. Alternator brackets, I remember something about motor mounts but that might have been related to the oil-pan.
Then he got into problems with clearance of the carb/hood, had to run a pizzapan air-cleaner.
IMHO, by the time they adjusted everything he probably could have purchased a normal block. Plus if he ever sells, there is a certain stigma attached to a "truck block"
Mooser

hugie82

You'll get the engine cheap and spend a fortune to make it work

Indiancreek

You'll have fit issues, but like was said you can make a big engine. The decks are .400 taller. Used to be, nobody wanted them, but now they are more in demand. I'm in the process of gettting one into a 73 for a guy now. I'm not ready to set it in yet so I can't answer your questions at this point.

SaberOne

I never knew tall decks were truck engines. I would love to install a 454-ish tall deck in my SS just because apparently, nobody else has done it.

derekderek

the advantage of tall decks it you have more room to stroke them.i mean really stroke them. not 496. 632 type displacements. they are also thick blocks that can take more than .060 bore. but in a corvette it is not worth the trouble. MK IV truck blocks can be had for 500. gen 6 roller blocks are lower than that as the trucks they came out of are more common.

Rescue Rogers

they were taller for and extra ring ...My buddy did a lot of research and its not worth it....dont do it

Pale Roader

Before i got into Corvettes, i always said that if someone put a gun to my head and forced me to build a BBC, it'd be a tall-deck 427. Coming from Mopar, i like tall decks, long rods, short strokes, and all that jazz. Even the tall-deck 427 is still half an inch shorter than a 426/440 deck. Hell, the lowdeck 383/400 is still taller than your truck block. My idea would have been a stock stroke/bore, 6.8-7.1" rods, light forged flattops, and some nice modern aluminum on top with small, tight, modern chambers.

Now that i own a Corvette, and am actually chewing on the idea ov a big block, there is just no way. No chance. Someone above said it perfectly: You'll get it cheap, and spend a fortune to make it work. I dont need a good rod ratio THAT bad...

Maybe in a custom vehicle, or something with a lot ov space. In a tight, hot Corvette? Nope.

I'd say that unless you absolutely need a 550cid engine cheap... and have the patience to source used tall deck parts, and have some fancy fabrication skills... pass.

7t9l82

Tall deck blocks became popular when "General" Lee Edwards took mountain motor pro stock from around 496 to 500 cubic inches all the way to about 600 and things really took off. But then they changed the weight break on tall deck blocks. So guys like me tried stacking head gaskets to get the same effect but that wasn't a great option. So I had a couple spacer plates made for me by a guy at the B&O railroad machine shop.
Those were the days of real innovators and those days are likely gone forever.
Building a tall deck today is all but pointless, if you want the baddest thing on the street get a Sonny Leonard motor. Sadly we lost him recently.
But if your heart is set on it have fun, that's what it's all about. Just put your block in a box filled with hundred dollar bills and have at it.

Pale Roader

Man... the way things are going with this tsunami ov Chinese garbage coursing in, we might get back to those days. I know personally, when i get deep into my car, i'm going to be modifying EVERYTHING... straight out ov the box. All the grief i've read about, heard about concerning new parts these last 15 years, i now consider ANY new part (that cant be confirmed to be made here, or long ago), to be a core... for rebuild/modification. Extreme, yeah, but i dont want to have to start one, or six ov those 'broke down at the gas station' threads...

If this bullshit gets any worse, i can see this place starting to look like Australia in the 90's... with people pulling diffs out ov delivery trucks and welding iron heads together...

68post

The largest practical GM 427T block displacement is 542ci and I'd bet not all blocks can go that far.
This would include using a 4.50" stroke crank, and being able to bore the non-siamese bores to +.125" (4.375").
The main advantages to the blocks are thick cylinder walls, and being able to use rods .4" longer for a better R/S ratio for less cyl wall loading.

LOL...thread is 10 yrs old.....

dmaxx3500

ive got a 555'' bbc ,
using a new gen 5 -502'' block
makes 700+hp on pump gas,looks stock and would fit in a c3 easy

Vette5311

I had one of these. The only part that’s any good is the forged crankshaft. The pistons are so heavy they make great door stops though.

keystonefarm

Yes they were . While in Vietnam in 69-70 for awhile I was stationed with Stabron 20. A riverine operation. They used a 24' long aluminum boat with two Mercrusier 427 Chevies in them with I/O drives. There were 20 boats built to augment the PBR's already in service that I had served on previously. The one I had was due for an engine changeout and when I pulled the 427's I got two new 427's to replace them. BUT they weren't 427's They were 482 ci tall deck blocks . I noticed the different intake and what I had to do to the water cooled exhaust to get them to fit. Turns out we had about 6 of the 482 tall deck complete engines as replacements along with a bunch of 427's !! They would move right along the rivers and canals of the Delta !! They had two 110 gallon fuel cells below the center of the boat. They were 9.0 to 1 compression so they could run on the 82 octane Mogas we used over there. They were the only river boats with gas engines . All the boats were brought back to the states in late 1970 and two still exist today and are being restored. --- Ken

Crider

I personally love the tall deck block for drag racing, currently have a 526" in my 55 gasser, and ran them blown on methanol in nostalgia funny car some years back. They make a great stroker, but no way I would put up with the grief of trying to get one to fit in a C3 if I were going to leave it at 427". It would be far cheaper and easier to build a 454 or even use a 454 block to make a 427, and it will fit in the car much easier.