I have a 70 chevelle. I dropped in a 350 H.O. Delux(330 HP) GM Goodwrench crate motor about 10,000 miles ago. It has the cast iron vortec heads.I ordered this motor with the roller rockers, cam and lifters they put in the 350 Ramjet motor. I couldn't afford the full Ramjet package at the time and am now debating about dumping the crapy Holley carb that came with the motor for either a better carb or fuel injection. However, I do not have much experience in this area.
Fuel injection would be a stretch on my budget but it is tempting for the reliability being as I drive my car daily. However another carb would be more affordable but I do not have a good feel for which carb would best fit may application and which one would be most reliable.
Anyone out there have some good suggestions?

Tim

How much do you want to spend on EFI?

I know it will cost over two grand for a fuel injection conversion kit and necessary hardware but is it worth it? I have no idea how good these bolt on conversion kits are and which ones are better than others. I am also curious to know if those of you guys that have spent the money to make this conversion feel that the performance and reliability is worth it or would I be just as happy spending much less for top flight carb.

Holley's aren't crappy, do some tuning

A good FI setup and knowledgable tuner can make a driveable car a pleasure to drive,but if you don't know what you're doing it can be a nightmare and may never run without expert help.Carb's are simple to work on and most chain parts stores sell parts if you break on a road trip. Try to find a MAP sensor for an Accel DFI system at Kragen. Injection systems can also reward with 5-10 MPG over a carb setup and cold driveabuility is greatly enhanced as well as NOS tuning if you are going that route. Everything has it's trade-off, it's a personal decision. I would like EFI but I'm real picky about tuning software and haven't found a system I'm totally happy with yet. F.A.S.T. is real close, also real spendy.

If your carb is properly tuned EFI might give a 2-3mpg increase at most. Like Dennis said the best thing is the drivability.

If the motor is staying at 330hp and you are adventurous you can look at doing a TBI retro fit from an 88+ Chev truck. Tons of info on the web. If you just want to buy something it's hard to beat the Holley Commander 950 setups. They can be had for under 1500$

Later
Steve

"reliability"hmmm i would much rather deal with a simple carb than ecm,fussy(injectors)and wiring.nothing wrong with a well tuned carb on a well tuned engine.get it right the first time and not have to deal with the electronics.of course everybody has there preference.my little 327 with my 600 edel starts every day.two pumps on the pedal when cold starts within 3-4 revolutions.
put that money someplace else unless your looking for fuel economy and a little better throttle response,some circumstances not even feeling a difference.just my bs'in
shane

I agree that you need to learn about tuning your carb. I'm not very good at it, but I've learned from a book and through searching numerous posts on Team Chevelle.

I was a Carter fan for years (aka Edelbrock), because (on the street) it was more forgiving of a poor tune than a Holley.

Tuning a Holley isn't as difficult as I once thought it was, it's just a bit messy sometimes. I've learned to love the things in the past year or so.

If you're still convinced that your Holley is crap, I'll give you $25 for it, sight unseen. ;)

I'd love to go to EFI. Holley's Commander system looks awesome to me. And FAST is pretty impressive too. The aftermarket systems seem to get better every year, so maybe by the time I can afford EFI they'll have perfected and simplified them to the point that I can understand and tune them to my engine. Until then, looks like I'll just have to continue running a carburetor.

It sounds like most of you guy feel I would be just as happy with a well tuned carb. I am sure my wallet would be. graemlins/hurray.gif I do not have any experience installing a FI system either so maybe it is best I stay away from that. graemlins/clonk.gif
I am not a pro at tuning a carb but I am no novice either. Nor am I anti Holley either. As a matter of fact I have never had any carb other than a Holley before. However the one I have now is a POS. I have had more trouble with this one and I am tired of jacking with it.
I have never tried any other brand of carb so I am curious what brand and model others swear by. Right now I am thinking of getting the Holley street advenger 670.

Thanks for the input guys graemlins/beers.gif

Tim

You can do a TBI injection setup using factory parts pretty cheap if you don't mind doing a little research, and it will be right at your power level. You don't even need to replace your Vortec intake, because Holley makes an inexpensive GM throttle body to four barrel intake adapter. Getting the parts and harness from the right donor is easy enough, then it's a matter of learning to tune it. It really isn't hard. If an old fart like me can figure it out, anyone can. smile.gif

I've got a factory TBI system in my car. It wasn't that hard to do and was probably about 3/4 the cost of a carb. I like it because I can tune without popping the hood. It also controls the lock-up in my 700R4 way better than any other method could. But then, the big expense is the programmer and a laptop or scantool for monitoring while driving which you don't have to have but it sure helps. I borrow a laptop from work and they have a programmer there.

Peter

Technically if both motors are tuned for best performance, you would be about the same power wise with a carb and EFI, but the EFI generally gives a broader torque curve, and better drivability. If you have a Pro built race carb you will have a bit more hp with that then EFI, but of course your part throttle response would be hurting.

I see no reason not to go EFI is you can afford it. Very far superior.

Originally posted by wanarace:
If your carb is properly tuned EFI might give a 2-3mpg increase at most. Like Dennis said the best thing is the drivability.
I get close to 18mpg on the Pontiac 455 in my sig with the FAST system. The big MPG gains happen in the low-load, cruising scenarios, e.g. on the freeway, when the engine doesn't need a lot of fuel.

Tim,
We currently have the Holley Projection 670 cfm on my sons chevelle. We also have the 970 cfm (4 barrel) complete. Throttle response is incredible, also picked up about 3 mpg average. Hey feel free to call me on my cell 713-249-0382, I am in Houston.

Regards,
Nick Tha P.... graemlins/hurray.gif graemlins/hurray.gif

Like everything else it varies. Depends how well the carb is tuned and how well the EFI is tuned as far as MPG changes. Certainly much, much easier (to me) to tune EFI for any conditions.