71 - 74 Corvette 454 Engine compartment size
 

1974 C3 Corvette 350 engine swap to 74 BBC 454 truck 3999289 casting number for 454 engine.

* understanding that the 74 Corvette was the last year of the BBC 454 LS4 engine with Auto TH400 Tranny.

The question is: on a 71 - 74 Corvette is the Engine compartment size the either if the car was a SBC 350 or BBC 454 from factory.

Second part to question: is the Corvette Engine compartment size on a 71 -74 Corvette difeerent from a 75 - 79 corvette.

Please help, as I'm ready to shoehorn a 74 Truck 454 engine (3999289) into a 74 Corvette Stingray.

Last question: should I use a Short Water Pump vs Long Water Pump?

Thanks in Advance to all,
New Member

I believe engine compartment size is the same among the C3 years, so basically any C3 will be able to get a big block inside it.

You should use short w/p in that application, also you have to use a different oil pan and possibly intake.

I could be wrong, but I beleive that the waterpump may also be Corvette specific, as opposed to standard short waterpump.

Personally I would spend the money in building a killer sbc before swapping in a BBC...its just a simpler package with a small block and far more convenient to work on....in addition to all the silly crap youd have to buy in bracketry and pulleys etc

Engine compartments are the same size.

No.

Purchase the 74 assembly instruction manual (AIM) and follow the installation diagrams for the big block option. The AIM shows how they did it and will also list the various parts you will need for the swap.

You will need a big block radiator for cooling and big block front springs for the additional weight. Truck blocks are a little taller than passenger car blocks so you may need a low rise intake manifold for hood clearance.

Good luck.

:thumbs:

Gentlemen thank you soo much for all the advise and Help
 

Really has been helping me out, :cheers: Happy New Years to all Corvette Lovers...

The Corvette is still American's Sexy Car...

Thanks again.

Hi c_s,
The only thing I'll add is that I believe the a/c option limits the room available for the engine since the blower duct work is larger then a non-a/c car.
This didn't stop the factory installation of a bb in any way, and may not affect you in any way either.
Happy New Year!
Regards,
Alan

FYI - Your block may have come out of a light duty truck, but its not what is considered a truck block.
Thats a good thing. Truck blocks are taller, heavier, and a general pain in the butt for no advantage unless your trying to build a major stroker.

3999289 block was used in Vettes so all the factory bits should just bolt up.

Thanks for the info, this is great news
 

Thanks for the info, this is great news.

This is great news
 

Thanks for the info, this is very good to kown.:rock:

You will need corvette specific pulleys and accessory brackets for your 454 as well as a short water pump. Somebody already mentioned the springs and rad. Add to this list a corvette specific oil pan and oil pump pickup tube. All these items will probably cost you $1200 or so.

GM never made the 454 in a tall-deck block; only the 427 and 366 md & hd truck engines came in that configuration.

I hope you are planning on rebuilding and doing some performance upgrades to that 454 before installation; otherwise you are going to be disappointed with it.

short water pump is a short water pump. There is not a corvette specific short water pump. I am also doing this swap and if you have patience in your search for the correct pulleys and brackets, it will cost less that $1,200. Also if you do some searching There are two others on here who have swapped in a light duty truck bb and used the same oil pan, but if you want the vette oil pan, I have seen a couple on ebay for a average of $50.

My waterpump speculation is from many years of reading catalogs while sitting on the toilet. If Im wrong, please forgive me, but please tell me why a manufacturer would make two of the same part for an additional application specified for Corvette, with a different part number?

http://www.tuffstuffperformance.com/...od/prd9010.htm

http://www.tuffstuffperformance.com/...od/prd8951.htm

simply because the corvette uses a different shaft diameter, I think it was 3/4 in. vs 5/8 in. for the passenger cars. If you want to retain the stock fan clutch then you need a corvette specific w/p with the larger shaft, so basically you could use any BB short w/p as long as you have the correct fan clutch.

If you go on each of the following auto parts stores : Napa , Advance , or Rock auto , They all offer replacement water pumps for the 1974 454 big block in either 5/8 or 3/4 shaft. In different brands too. I am sure if you go with the 3/4 shaft, it is stronger than the 5/8.

I did a 74 with a 427bb and 4speed. Fit right in DrRebuild supplied all the brackets and mounts.

For what its worth, I too dropped in a 454 with the truck oil pan. I didn't know to worry about it. It fit fine.

I even ran with all the truck pulleys for a while, (had to re-wire for alternator). No A/c, no power steering though.