Since I live in California and want to get a super fast car, I want to get one that's smog exempt. That means 1975 or earlier. I figured 1973 or 1974 to avoid any problems with 1975 cars that had cats.

I want to know if these years cars would be compatible with putting in larger than 454 turbocharged big block with an automatic trans.

What problems am I looking at especially as far as the size of the engine bay.

 

Do the words "no room at the inn" help? I have a '74 with an LS-4 and all accessories (A/A, P/S, P/B) and there wouldn't be room enough in there for a cat to curl up. Even if you removed the accessories, I think it would still be a bit tight.

Steve

 

454 with a huffer no prpblem except for a hole in hood. The weak link will be the rear end and suspension. I had a 66 roadster with a 395/425 and the gears held up ok but the trailing arms had a lot of problems.

 

I have seen a 502 in a C3, fits OK. The turbo is the problem. There isn't a lot of room on the sides, and you would need custom headers, etc. The turbo guys on this forum spent a lot of time and $ on fabrication. You can do anything to a C3 if you spend enough $, but a superpower engine is going to need a beefy drivetrain also, and after a certain point you will start breaking rear diffs and axles.

As they say "Speed costs money. How fast do you want to go?"

Rick B.

 

Ask Big 632 for some pics of an engine he put in a '73.

I still think he can get more motor in there.


More pics Mike

 

THe 73 and 74 are relatively the same size in the engine bay. Be sure to get one without ac. I don't know about a big block, but i've seen it done on a 1969 small block...





Note: this all fit under a small block hood with the hinges removed.

 

Just one small point....they are not smog exempt. They may be exempt from having to be tested to get/renew liscense but they are not exempt from the law. They can still get you at a road block check, a roadside sniffer, or to being stopped as a gross polluter.

tom...

 

Never ever seen a block check, roadside sniffer or been stopped as a gross polluter. Lived for 10 years in LA county, and the past 9 in san luis obispo county.

 

The odds are highly in your favor that you would not be stopped, but it is a possibility. Just that the fact of the matter is that the cars are NOT exempt from the emission standards.

 

Believe me there is no room under the hood. I even had trouble checking the power steering fluid which was down and covered by an alternator bracket if you checked it when hot you got burned. Spark plug installation was a nightmare went through wheel wheels to change the splugs. I found different brands of plugs in this motor from previous owner/owners must have been able to install and not install... The fust box was located way way up in no man's land ...The heat that you get from the motor will keep you warm not just in the winter but ALL the time. As you probably already know all of these Corvettes from 63 to 82 had caliper leakage so stainless steel calipers are the fix. Get big block get less options and just have a clean engine in there and a fan belt and that should be good like I have seen some 69 427's like that. I haven't seen any 70 to 74 motors which are 454's like as clean as a 69.
Also another problem is vibration. The car has a tendency to shake itself apart loosen up all the screws.

If you want a superfast car get a C-6 I just got one and it fulfills the 454 auto Coupes power and is actually faster in all performance categories 0-60, quarter miles, top end speed of 186, better suspensions, tires = superior handling ..more confortable and great gas mileage from 24 and up. The 454 you will get like 7-10 miles per gallon and it will not run close to the new ones of today in those days 130 miles was alot for a car to top out at ...

 

Also got higher bumper standards the 73 has chrome rear end and front plastic urethane type. First year they put bars across doors inside for extra protection.
74 both front and back were of that urethane type bumper. No chrome. The 74 has a ugly seam in the middle of the rear you can't miss it.

 

can you translate that in laymens terms?

 

I have a 73 and think its the prettiest C3.

Gale banks set alot of records in a twin turbocharged 454 in a C3. So it can be done, but it will take some time and planning. Not exactly a bolt in.

In turbochargers by hugh maclinnes:
on page 20 there is a pic of some turbos mounted low on a roadrace corvette.
on page 59 is a pic of a twin turbo installed in a C3, but it looks like a small block, Its a blow through carbuerated system.
on page 91 is the pic you are looking for gale banks twin turbo 454 C3.

So it has been done before, long before.

 

with a big block I would definitely look into mounting them low with some kind of scavenger system to scavenge the oil. Kind of like the callaway C4s and the lingenfelter C5s. with an automatic you should have lots of room down near the gills.

 

Will you do all or most by your self - if no then at least I would rather drop in a 540BB NA; would be much easier to do and it takes no more room than the original BB in a 1973. I have in my BB L-88 hood and L-88 intake + 850DB Holley - fits still fine in.

I do not recommend stock C-6 if you like the real feelings and shakings of a bad rat BB - and a proper one beats C-6 easily, but of cource has no change if you do something else than drive straight forward...

 

Yep - the underhood area is tight with a big-block in there.

I saw something neat the other day on TV - I think it was Two Guys Garage. They installed a turbo on a late-model Camaro. The turbo was at the rear where the mufflers would go. A pipe ran the air back up front to the motor.

Now, we've got room back there! And with a turbo, you wouldn't need the mufflers. The only problem would be plumbing the pipe to return the air to the motor. And, would you go twin turbo?

Good luck with whatever you do.

 

get the 73 over the 74 far superior rear bumper.