454 swap into a 1979 vette

[TSabr88]

my father bought a vette back in august and blew up the 350 3 weeks later and now hes getting a 454 to put in it in a few weeks i was wondering how much modification has to be done in order for the motor to fit. also i'm new here so i might as well tell ya all a bit about the vette its a pearl white 79' it had a rebuilt L-48 with an Edelbrock Torker II intake, Double hump heads, hooker headers, it had a slightly larger cam than stock but i cant remember the specs on it and the thing that killed it all off was the Edelbrock 800CFM carb...#4 and #6 pistons broke apart lightly just enough to smash the plugs and then part of the edge of #4 piston broke off making a horrible noise when we decided to rip the motor out and replace it with a 305 and used the Torker II intake and hooker headers on it and its now not as much as a pleasing car it use to raise up when you would cruise at 70MPH and just punch it and lay into it which is why we are putting in the Big block for even more power

 

[BTWard454]

I'm working on a swap pretty close to yours, except I'm putting a 454 into an 81, in which the engine compartment layout is similar, so I'm assuming the big block will at least fit there with a few mismatched parts. I'm not sure how this will all translate to your 79, but for my Vette, I started with the small block motor mounts, the big block ones made my engine set too high, next, I bought a set of Hedman headers that they listed as being for a 78-82 big block,with 1 7/8" primaries, and to my suprise, they fit perfectly. That is where the fun really began...For the most part, I used the engine bracketry from a 74 model, but from what I was told then, some of these parts are being discontinued and are now getting hard to come by. My small block crankshaft pulley and waterpump pulley wouldnt line up with the big block stuff, so I ad to buy both of those too....My waterpump pulley is off a 74, but I couldnt locate a crank pulley off a 74, so I wound up using one off of a 68 L-88. To finsh it off, I believe the power steering pump pulley is off a 74 too. I'm not sure if youre planning on keeping the A/C, but in my case there was no room so I scrapped all of it.
Depending on how you build your 454, you might want to think about swapping out your radiator for a 4 core instead of a 3 core. I built my engine to where I'm pushing around 530 horsepower or so, so extra coowas a foregone conclusion. I went ahead and got the bigger radiator, and switched to dual electric pusher fans the fit neatly on the front of the radiator
I hope some of this might help you out a little

Brent

 

[TSabr88]

Thanks Brent that info really helps alot i was kinda nervous about gettin into this wondering if everythign would clear and bolt up with out much modification the guy who use to own this vette didn't go for cheap parts any where and it has a 4-core radiator now that you bring that up bu just a flex-fan bolted to the front of the engine it also use to have a Holley fuel pump in the center compartment in the back with fuel lines running into the cab

 

[bobherr46]

Someone from Olney,IL(East Central IL) has been advertising a 74 vette in a local shoppers paper but the cell phone # they list does not work. Would that be you? - Bob

 

[TSabr88]

no that is not me i live over by Champaign, IL

 

[Deadlego]

Did you all have to move the motor mounts? I have been thinking about this. but not sure

 

[6880 Mike]

...use to have a Holley fuel pump in the center compartment in the back with fuel lines running into the cab...

Bad idea. You do not want gasoline brought into the interior of the car.

Purchase the assembly instruction manual (AIM) for any year with the big block option (68-74). The AIM will show the factory installation of the big blocks, list all the original parts and parts numbers, tell you how and where the big block installatino differed from the small block cars, and show you how to install one in your '79.

You will want the big block front springs to carry the additional weight and the 4 row radiator and shroud for the necessary cooling. AIM will show these, plus the additional bracketry, pullies, etc., the big blocks require.

 

[TimAT]

I'm with mike- running ANY fuel into the passenger compartment is inviting disaster.

Your motor mounts will be the same, but you'll need all the front engine brackets for a BB. And of course the exhaust system. Everything else will bolt up no problem. All the factory brackets for a BB are available thru different vendors. but you could also go with a serpentine belt from March or contact Alan Grove Enterprises in Louisburg KS for aftermarket mounting brackets. No affiliation, but I have used their stuff in the past and it's good quality.

 

[Rebelrob]

Did your 81 come with a 3 core radiator? Not sure what mine is.
Was thinking of adding another core if thats possible or just get new aluminum radiator.

I'm working on a swap pretty close to yours, except I'm putting a 454 into an 81, in which the engine compartment layout is similar, so I'm assuming the big block will at least fit there with a few mismatched parts. I'm not sure how this will all translate to your 79, but for my Vette, I started with the small block motor mounts, the big block ones made my engine set too high, next, I bought a set of Hedman headers that they listed as being for a 78-82 big block,with 1 7/8" primaries, and to my suprise, they fit perfectly. That is where the fun really began...For the most part, I used the engine bracketry from a 74 model, but from what I was told then, some of these parts are being discontinued and are now getting hard to come by. My small block crankshaft pulley and waterpump pulley wouldnt line up with the big block stuff, so I ad to buy both of those too....My waterpump pulley is off a 74, but I couldnt locate a crank pulley off a 74, so I wound up using one off of a 68 L-88. To finsh it off, I believe the power steering pump pulley is off a 74 too. I'm not sure if youre planning on keeping the A/C, but in my case there was no room so I scrapped all of it.
Depending on how you build your 454, you might want to think about swapping out your radiator for a 4 core instead of a 3 core. I built my engine to where I'm pushing around 530 horsepower or so, so extra coowas a foregone conclusion. I went ahead and got the bigger radiator, and switched to dual electric pusher fans the fit neatly on the front of the radiator
I hope some of this might help you out a little

Brent

 

[Vettehead Mikey]

This post has been dormant for over 5 years if you're expecting answers from the OPs.