I just purchased an 84 jag convertable with a 97 surburban 5.7 liter vortec (less than 12K miles) that has been converted to a Carter 650 CFM carb and Edelbrock intake. The exhaust manifolds are 72 vette. No other changes were made (timing, cam, etc.) With  this setup should I be concerned about anything? This setup has less than 3000 miles on it and if I need to do anything else I want to do it ASAP. I want 350 - 400 HP with adequate torque, both of which I think I have now.

I am open to any suggestions at this point.  

The 350 Vortec with the mods you have is not making anywhere near 350/400 hp, more like 250 to 280, maybe 300.

You must live somewhere that doesn't do SMOG inspections as what's been done here violates a lot of laws, federal on down.

To get more power out of this engine you'll need more cam, a lot more cam. You need at least a 10185071 with 208/221 duration combined with 1.6 roller rockers. This cam/lifter combination (so will 1.5 ratio rockers) will push the lift limits of Vortec heads requiring that the guides be machined to increase clearance for the spring retainers. Springs will also need to be replaced with 12551483 (LT-4) or 10212811 and will also require some machining of the head. The pressed-in studs should be replaced with screw in styles to insure the new springs don't pull somebody out and while your there, it's not a bad idea to install pushrod guides that way you can run ungiuded rockers which behave better as the lift goes beyond .450 inch, this requires hardend pushrods which if you running factory lifters need to be the short length.

The compression needs to be a solid 9.5 to 1, if this engine is running a composition head gasket you can switch it for a steel shim style and pick up a much needed half ratio, otherwise you can mill it .030 inch.

The Carter 650 will be reaching out on the top end. I'm not a fan of the Edlebrock/Carter but if you want to stay with it they have 750 or 800 CFM versions available. You'll need to look into the distributor if it already isn't an aftermarket unit.

This combination will deliver a solid 350-370 hp.

Bogie 

Thanks for the info. I had a feeling I wasn't near 350 (tho that is the advertised HP from the seller). I DO live in an emissions test area (GA) but I am going to try to get an exemption for this car as a show car or gray market car. I do have the option of getting another EFI system (original is gone)from another 350 vortec from the seller for free but am intimidated by the installation complexity. I have heard the nightmare stories.

If I can get the waiver on emissions should I stay carburated and make your changes (including a 700-750 CFM carb) or should I convert back to EFI?

This is my first project car in  over 5 years and first v8 in over 10. I am not up to speed on what after market parts work best, work with each other and what is the optimum for this engine. I do plan on showing the car but I will drive it weekly also.

Thanks again for your input.  

I haven't looked at Georgia's emission laws, most states have adapted those of California Air Resources Board (CARB). However, Ga. may allow exemptions that go beyond CARB.

Basically CARB says you can put almost anything into anything so long as the engine/driveline are the same year or newer as the vehicle and includes all emissions equipment installed and functional as the engine/driveline were qualified with. It further states that the emission system requirement must be that which is the more stringent engine/driveline or chassis. This is a way of saying it's not legal to put a truck engine/driveline into a passenger car, which of course you have.

If your engine came with its original transmission, then having kept the EFI would have been a small problem as the system is essentially self contained needing only + 12 volt power from the chassis and a place to mount the computer and sensors.

California (where I don't live, I'm further up the coast where it rains all the time) has a legal process for hot rods that includes an engineering referee and lots of techincal help for the back yard mechanic or professional. SEMA (Speed Equipment Manufacturers Association) has worked very hard and spent huge sums of money to make all this possible for us. I would suggest that you get a hold of CARB and get their rule book on swaps and rods to use as a guide.

If all they do is sniff your exhaust, I'd get this checked out at a private garage. If it's legally clean, just don't volunteer any info to the test people or get an exemption if your state allows it, register in a county where they don't check for emissions, what ever.

Fuel injection works much better than carburetion, you get more power, better fuel economy, and lower emissions. When the mixture is held stoichiometrically correct, emissions go way down. It is absolutly amazing how fast and how much the bad stuff is formed when the mixture gets just a fraction off 14.7 part air to one part fuel. A carb cannot come close to holding these tolerences.

The original EFI for your engine is a sequential timed unit, these are nice because they allow a lot more cam overlap without the loss of raw fuel out the exhaust; again more power, better mileage, lower emissions. 

I recommend you contact Mike Knell at

http://www.jagsthatrun.com/

He's one of the nationally recognized gurus of legal engine/driveline swapping of Chevy power into almost anything driven on the street. He has several books (those on swapping the SBC into S-10/15 pickups are a wealth of info and the data slops over what you need for a Chev-Jag swap.

If the guy you bought the car from is willing to part with the EFI for free, take it home. Try to get the engine hardware, wire harnesses, sensors and computer as stuff like the harnesses are mighty expensive if you go to "Painless" and tricky to get everything at the local wrecking yard.

Bogie

Thanks! This info helps alot.