saouad

so my 1984 corvette motor is no longer functioning, has cracked heads and block, needless to say it was do to faulty wiring for the fan which overheated the car when i had lent it to my brother to drive... but now to the point, what engine should i install I have a 406 laying around but i am nervous about the clearance of the carb under the hood and how hard the conversion of the crossfire to a carbed 406 would be. I am looking to get a little over 400 hp to the rear wheels. The only things altered on the 84 is a borla exhaust and some long tube headers, other than that it is all stock. Looking forward to your help

wilcar

Not a hard conversion but carb clearance is going to be close. You will need a low rise intake and probably a 2 inch high air cleaner and it may just fit although mine still rubbed on part of the hood. You need to have at least a 1/4" -1/2" carb insulator gasket/spacer to ward off fuel percolation problems. With 400 hp to the year wheels you will need to beef your rear end up if you are planning on racing it.

saouad

for the rear end i have the dana 36 since its an automatic, switching it to the dana 44 will it be enough? what are your suggestions

cv67

400 at the tire with a 406 put a carb on it forget about the CFI

383vett

Go for the 406. Makes my 84 go.

Tom400CFI

I agree that 400 at the wheels won't happen with the stock CFI intake. You could get 300 at the wheels but that's about it.

I feel that 400 at the wheels with something that looks like CFI is totally obtainable, however if you're willing to do some work. Using an Edelbrock SY1, and Offenhauser crossram, or the Renegade (if you can get one), and then a solution for control (upgraded ECM or stand alone) you could meet your goals pretty economically, and still retain EFI and something that looks like CFI (and fits under the hood).

If I were you, I'd do the 400 swap, put the CFI on it w/bigger injectors just to get it running, then work on an induction solution after that.

Purple92

Before you make the decision, think about how you use the car, the emissions laws you have to deal with and the budget.

If you have emissions inspections - the Carb'd 406 will be an issue. And I strongly doubt the carb motor will get the fuel mileage of an injected motor.

However, if this is a 2nd car, and emissions are not an issue, the carb set-up will probably be a LOT easier to make a driveable car out of. Other posts have talked about carb height. Stick with something like an Edelbrock Torquer II intake, and a drop base low height air cleaner, or one of the air cleaners that are designed for low clearance situations and you'll probably be OK. Plan to add a fuel pressure regulator that can handle the pressure the current fuel pump puts out, and convert it to the 5 psi or so a Holley or Demon carb likes.

If the motor you have is "complete", an intake and carb will run around $700. Not cheap - but not exactly crazy money either. 1 HP per cubic inch on a SBC isn't a real problem with a decent set of cylinder heads. Making an early EFI system work on a bigger displacement motor with a different cam than the factory had installed is not going to be a walk in the park. Count on bigger injectors (figure $400/set), and then you get to deal with playing with ignition timing etc. Sure it can be done, but it all takes time, and the ability to figure out where you are so you can adjust things the right way. Decent carbs come out of the box fairly close, and can be tuned on a chassis dyno (one equipped with wideband O2 sensor) with a screwdriver and a $20 box of jets); Not so a factory EFI system, where PROM burners are frequently needed... The speedo and Tach will probably work fine, but Yes, some of the other gauges probably won't .

Bottom line - sit down and do some thinking about both options, and how much work it will be to make them work. Also think about You just getting a GM 350 long block, and popping that in with the factory cam and EFI.

As for the Dana 36 rear - those are stronger than most people give them credit for. If you're planning to do 4,000 RPM clutch dumps with slicks - it won't live, but I wouldn't call it "mandatory" to change it out immediately if you're making 400 HP. Take it a little easy in 1st gear, and it'll probably live for quite a while.