mrichi

Hi I'm thinking about putting a 454 in my 79 Vett which is automatic

Whats involved with this modification is it just a straight bolt in job


The 454 engine iam looking at is based on the same block as the early 454's

CWyler

There are many on this board who have done a BBC swap, search the forums. Its a fairly bolt in job as the mounts for the SBC and BBC are the same.

John 65

Did the swap in my 77, no big surprises.
Big block exhaust and cooling changes obviously and to save $$$ you can even use non corvette brackets and pulleys if so desired.

I was able to use my stock 77 hood also.

The conversion was well worth it. Lots of fun.

mikem350

Look in the parts catalogs like Corvette Central for pictures and lists of new parts needed. Like fan and shroud, brackets belts. Small stuff like fuel lines, trans kickdown brackets, throttle attachment.

Dizzy is the same. Front end may sag requiring new BB springs.

mrichi

Is it best to use the standard exhaust manifold ? I am thinking a 454 with extractors would be a tight fit

Also my 79 has air con and the radiator is in good order with no overheating problems ,that said would I need to upgrade my radiator ?

Easy Mike

FWIW: all factory big block installations used a heavy duty radiator for cooling purposes. If you want to make the swap, it is something you need to consider.

Tom73

Don't forget the suspension. With the additional weight you will need to upgrade the springs & shocks (front & read).

Tom...

BBCorv70

I'll add to install a factory style big block radiator will require a new radiator support as well. The big block radiator support is different.

CWyler

I'll agree with these guys that there are mods to be done, none of which are incredibly expensive nor difficult.

The13Bats

Sometimes things that seem a must are not really,

In my case I have a 69 sb car that has a 454 transplanted into it, my radiator and support is still the small block ones, in my case I did go with a high performance custom built aluminum radiator...but "IF" I had a good working radiator and the 454 wasnt too mean I would "try" the radiator because I never spend a penny "just because" I research it, try it out then if I need to spend the penny I do.....

The power steering lines are different sb to bb,
The stock corvette pulleys and belts and brackets do not thrill me much, mine has a cheesy extra belt, crank to waterpump that has no way to adjust tention on, but I can't afford the modern serpent set ups so...

If you tackle this swap and try to make it all stock that changed year to year with bb's and will be harder, but if you do it custom and mod things here and there to upgrade and improve then you will really have a sweet fun to drive 79...

LS4 PILOT

Corvettes 65-74 had a unique set GM BB exhaust cast iron manifold . You'll need them , reproduction, used or set of headers . Other cars usede a diff exhaust system .

I'd use a PASS stamped block , as opposed to a truck stamped cast block.

Low rise iron intake and low rise air cleaner of some variety to keep stock hood. If that is important

You want 454 vette sway bar , F41 springs , rear sway bar , large radiator, , hoses , new belts , all your pulleys , brackets .

You might want to buy a 73-74 AIM Manuel .....it has pics of all the brackets hoses , parts, numbers , configuration s .....for latter 454 car application

That will get you started

You'll like it

CWyler

Oh my, we will have to agree to disagree here. See red for my opinion.

mrichi

Will I still be able to use my stock 79 air conditioner compressor ?

68/70Vette

The all cast iron big block is really gross in my opinion. To do the conversion right, I think you have to buy aluminum cylinder heads, an aluminum intake manifold, and what the heck..an aluminum water pump. My 70 BB came with cast iron everything....very gross.

hwcoop

I just performed the swap in my 73 4 spd. I didn't even take the hood off or pull the rad


Being an L82 car it had a 2.5" exhaust and the heavy duty U-Joint straps on diff and driveshafts
During my chassis restoration a few years ago i had upgraded all the suspension with heavier springs, sway Bars, Poly bushings , used a new Corvette Central 2.5" exhaust with Stainless Magnaflow mufflers.

For the swap i found a Gen IV 454 out of a pickup truck that had been on propane and performed a complete rebuild on it. (10.5 Speedpro pistons, .030 over, ARP Crank studs, head & rod bolts,Rods resized, aligned honed, crank turned .010/.010, Procomp large oval port heads, Crane cam, Comp cam roller rockers, pushrods, guide Plates, edelbrock performer intake with squarebore adapter plate, QuickFuel 750cfm vac secondary carb, HEI Tach drive distributor with MSD wires)

With mine being a no option car i didn't have to worry about power steering, AC etc...just needed to spin the water pump and alternator.

I reused the 350 engine mounts, Bellhousing, upper rad hose, starter, added an HEI Tach drive distributer and staying with the M21 for now.
For intake i'm running a Performer with Quick fuel 750 carb, and needed a drop base air filter with 2"x 14" element to get hood clearance
This photo was with a qjet and 3" element for the inital install / fire up



I had upgraded the Radiator last summer to a Dewitts perfect fit, no problems with cooling


I used a set of Headman 68090 headers, I did need to massage mine a bit for clearance by the frame rail and steering box


replaced my parts store Taiwan clutch with something a little better


I just managed to get my cam break in done and a few short road tests before the snow started last year, looking forward to some fun summer cruising!

Overall not too difficult of a swap to do, gather up all the parts you need first then you can do the swap over a few days.

Procrastination Racing

The cast iron will go right in and cause no issues with installation. Some headers have issues with the air conditioning box and usually need to be dented to clear for installation on the steering box. They also put a lot of heat into the steering box and master cylinder. On the race car, we ran aluminum heat shields we made to keep heat off of them.

However, performance is much better with headers.


Truck blocks. There are two types. One is a passenger block that has a truck assembly code that went in light trucks - C10, C20, etc. The other is a tall block that went in big trucks. The tall block is what is meant by "truck block". The tall block uses a different intake and can make for clearance problems in an already tight space. And they are heavier. While drag racers once used truck blocks due to longer rod lengths to produce more power, on the street you will never need that.

A Performer intake is not a high rise intake. All air cleaners in Corvettes are a dropped based. And you can only drop so much before you restrict the air space over the top of the air horn.


The '73-'74 manual would just help simply the installation.

Most places sell pulleys and brackets for long pumps, not short pumps, which left the regular line of Chevrolets in 1969. So getting the pulleys and brackets to fit the short pump and fit in the Corvette can be a hassle. This just simplifies it with a list of parts that work.

I don't agree on all the suspension parts either. The F41 was the heavy duty suspension. It can be a bit stiff for daily driving and won't impress your girlfriend/wife.

A rear sway bar is needed if he expects to ever driving curvy roads. Otherwise the understeer will be unpleasant. Don't go crazy as the stock big block rear bar wasn't very thick. It doesn't take much. And he may need regular big block springs but the '79 springs are so tall, they may just left the car settle to a more natural height.

By the mid '70s, they all had the full width copper radiator but they may not have as many rows. But radiators have improved so a high performance three row core may be more efficient that an old real big block radiator. I'd go with the stock '79 one first and see if it works before spending the money. Swapping radiators isn't a big deal. Loosen and push back the shroud, lay a thick piece of cardboard over the fan, and then slide the old radiator up and out. Slide the new one in, pull the cardboard, and put the shroud back on.

The13Bats

hwcoop

Except since 74 was the last year for the 454 the AIM would have all the related drawings etc for the big block install.

And in regards to all the cast iron comments, the lighter the better!... I read somewhere that a BBC with aluminum Heads, intake and water pump was only about 80-100lbs heavier than a small block.. Still, 500ft lbs of torque in a 3,500lb car will move!

mrichi

Thanks for that your info has been very helpful the engine looks great

Tom73

In '73 the 454 added 211 lbs over the base L48 small block.